Reference documentation and code samples for the Retail V2 API class Google::Cloud::Retail::V2::SearchRequest.
Request message for SearchService.Search method.
Inherits
- Object
Extended By
- Google::Protobuf::MessageExts::ClassMethods
Includes
- Google::Protobuf::MessageExts
Methods
#boost_spec
def boost_spec() -> ::Google::Cloud::Retail::V2::SearchRequest::BoostSpec
-
(::Google::Cloud::Retail::V2::SearchRequest::BoostSpec) — Boost specification to boost certain products. See more details at this
user guide.
Notice that if both [ServingConfig.boost_control_ids][] and SearchRequest.boost_spec are set, the boost conditions from both places are evaluated. If a search request matches multiple boost conditions, the final boost score is equal to the sum of the boost scores from all matched boost conditions.
#boost_spec=
def boost_spec=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::BoostSpec
-
value (::Google::Cloud::Retail::V2::SearchRequest::BoostSpec) — Boost specification to boost certain products. See more details at this
user guide.
Notice that if both [ServingConfig.boost_control_ids][] and SearchRequest.boost_spec are set, the boost conditions from both places are evaluated. If a search request matches multiple boost conditions, the final boost score is equal to the sum of the boost scores from all matched boost conditions.
-
(::Google::Cloud::Retail::V2::SearchRequest::BoostSpec) — Boost specification to boost certain products. See more details at this
user guide.
Notice that if both [ServingConfig.boost_control_ids][] and SearchRequest.boost_spec are set, the boost conditions from both places are evaluated. If a search request matches multiple boost conditions, the final boost score is equal to the sum of the boost scores from all matched boost conditions.
#branch
def branch() -> ::String
-
(::String) — The branch resource name, such as
projects/*/locations/global/catalogs/default_catalog/branches/0
.Use "default_branch" as the branch ID or leave this field empty, to search products under the default branch.
#branch=
def branch=(value) -> ::String
-
value (::String) — The branch resource name, such as
projects/*/locations/global/catalogs/default_catalog/branches/0
.Use "default_branch" as the branch ID or leave this field empty, to search products under the default branch.
-
(::String) — The branch resource name, such as
projects/*/locations/global/catalogs/default_catalog/branches/0
.Use "default_branch" as the branch ID or leave this field empty, to search products under the default branch.
#canonical_filter
def canonical_filter() -> ::String
-
(::String) — The default filter that is applied when a user performs a search without
checking any filters on the search page.
The filter applied to every search request when quality improvement such as query expansion is needed. For example, if a query does not have enough results, an expanded query with SearchRequest.canonical_filter will be returned as a supplement of the original query. This field is strongly recommended to achieve high search quality.
See SearchRequest.filter for more details about filter syntax.
#canonical_filter=
def canonical_filter=(value) -> ::String
-
value (::String) — The default filter that is applied when a user performs a search without
checking any filters on the search page.
The filter applied to every search request when quality improvement such as query expansion is needed. For example, if a query does not have enough results, an expanded query with SearchRequest.canonical_filter will be returned as a supplement of the original query. This field is strongly recommended to achieve high search quality.
See SearchRequest.filter for more details about filter syntax.
-
(::String) — The default filter that is applied when a user performs a search without
checking any filters on the search page.
The filter applied to every search request when quality improvement such as query expansion is needed. For example, if a query does not have enough results, an expanded query with SearchRequest.canonical_filter will be returned as a supplement of the original query. This field is strongly recommended to achieve high search quality.
See SearchRequest.filter for more details about filter syntax.
#dynamic_facet_spec
def dynamic_facet_spec() -> ::Google::Cloud::Retail::V2::SearchRequest::DynamicFacetSpec
-
(::Google::Cloud::Retail::V2::SearchRequest::DynamicFacetSpec) — Deprecated. Refer to https://cloud.google.com/retail/docs/configs#dynamic
to enable dynamic facets. Do not set this field.
The specification for dynamically generated facets. Notice that only textual facets can be dynamically generated.
#dynamic_facet_spec=
def dynamic_facet_spec=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::DynamicFacetSpec
-
value (::Google::Cloud::Retail::V2::SearchRequest::DynamicFacetSpec) — Deprecated. Refer to https://cloud.google.com/retail/docs/configs#dynamic
to enable dynamic facets. Do not set this field.
The specification for dynamically generated facets. Notice that only textual facets can be dynamically generated.
-
(::Google::Cloud::Retail::V2::SearchRequest::DynamicFacetSpec) — Deprecated. Refer to https://cloud.google.com/retail/docs/configs#dynamic
to enable dynamic facets. Do not set this field.
The specification for dynamically generated facets. Notice that only textual facets can be dynamically generated.
#facet_specs
def facet_specs() -> ::Array<::Google::Cloud::Retail::V2::SearchRequest::FacetSpec>
-
(::Array<::Google::Cloud::Retail::V2::SearchRequest::FacetSpec>) — Facet specifications for faceted search. If empty, no facets are returned.
A maximum of 100 values are allowed. Otherwise, an INVALID_ARGUMENT error is returned.
#facet_specs=
def facet_specs=(value) -> ::Array<::Google::Cloud::Retail::V2::SearchRequest::FacetSpec>
-
value (::Array<::Google::Cloud::Retail::V2::SearchRequest::FacetSpec>) — Facet specifications for faceted search. If empty, no facets are returned.
A maximum of 100 values are allowed. Otherwise, an INVALID_ARGUMENT error is returned.
-
(::Array<::Google::Cloud::Retail::V2::SearchRequest::FacetSpec>) — Facet specifications for faceted search. If empty, no facets are returned.
A maximum of 100 values are allowed. Otherwise, an INVALID_ARGUMENT error is returned.
#filter
def filter() -> ::String
-
(::String) — The filter syntax consists of an expression language for constructing a
predicate from one or more fields of the products being filtered. Filter
expression is case-sensitive. See more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
#filter=
def filter=(value) -> ::String
-
value (::String) — The filter syntax consists of an expression language for constructing a
predicate from one or more fields of the products being filtered. Filter
expression is case-sensitive. See more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
-
(::String) — The filter syntax consists of an expression language for constructing a
predicate from one or more fields of the products being filtered. Filter
expression is case-sensitive. See more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
#labels
def labels() -> ::Google::Protobuf::Map{::String => ::String}
-
(::Google::Protobuf::Map{::String => ::String}) — The labels applied to a resource must meet the following requirements:
- Each resource can have multiple labels, up to a maximum of 64.
- Each label must be a key-value pair.
- Keys have a minimum length of 1 character and a maximum length of 63 characters and cannot be empty. Values can be empty and have a maximum length of 63 characters.
- Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed.
- The key portion of a label must be unique. However, you can use the same key with multiple resources.
- Keys must start with a lowercase letter or international character.
See Google Cloud Document for more details.
#labels=
def labels=(value) -> ::Google::Protobuf::Map{::String => ::String}
-
value (::Google::Protobuf::Map{::String => ::String}) — The labels applied to a resource must meet the following requirements:
- Each resource can have multiple labels, up to a maximum of 64.
- Each label must be a key-value pair.
- Keys have a minimum length of 1 character and a maximum length of 63 characters and cannot be empty. Values can be empty and have a maximum length of 63 characters.
- Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed.
- The key portion of a label must be unique. However, you can use the same key with multiple resources.
- Keys must start with a lowercase letter or international character.
See Google Cloud Document for more details.
-
(::Google::Protobuf::Map{::String => ::String}) — The labels applied to a resource must meet the following requirements:
- Each resource can have multiple labels, up to a maximum of 64.
- Each label must be a key-value pair.
- Keys have a minimum length of 1 character and a maximum length of 63 characters and cannot be empty. Values can be empty and have a maximum length of 63 characters.
- Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed.
- The key portion of a label must be unique. However, you can use the same key with multiple resources.
- Keys must start with a lowercase letter or international character.
See Google Cloud Document for more details.
#offset
def offset() -> ::Integer
-
(::Integer) — A 0-indexed integer that specifies the current offset (that is, starting
result location, amongst the Products
deemed by the API as relevant) in search results. This field is only
considered if page_token
is unset.
If this field is negative, an INVALID_ARGUMENT is returned.
#offset=
def offset=(value) -> ::Integer
-
value (::Integer) — A 0-indexed integer that specifies the current offset (that is, starting
result location, amongst the Products
deemed by the API as relevant) in search results. This field is only
considered if page_token
is unset.
If this field is negative, an INVALID_ARGUMENT is returned.
-
(::Integer) — A 0-indexed integer that specifies the current offset (that is, starting
result location, amongst the Products
deemed by the API as relevant) in search results. This field is only
considered if page_token
is unset.
If this field is negative, an INVALID_ARGUMENT is returned.
#order_by
def order_by() -> ::String
-
(::String) — The order in which products are returned. Products can be ordered by
a field in an Product object. Leave it
unset if ordered by relevance. OrderBy expression is case-sensitive. See
more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
#order_by=
def order_by=(value) -> ::String
-
value (::String) — The order in which products are returned. Products can be ordered by
a field in an Product object. Leave it
unset if ordered by relevance. OrderBy expression is case-sensitive. See
more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
-
(::String) — The order in which products are returned. Products can be ordered by
a field in an Product object. Leave it
unset if ordered by relevance. OrderBy expression is case-sensitive. See
more details at this user
guide.
If this field is unrecognizable, an INVALID_ARGUMENT is returned.
#page_categories
def page_categories() -> ::Array<::String>
-
(::Array<::String>) — The categories associated with a category page. Required for category
navigation queries to achieve good search quality. The format should be
the same as
UserEvent.page_categories;
To represent full path of category, use '>' sign to separate different hierarchies. If '>' is part of the category name, please replace it with other character(s).
Category pages include special pages such as sales or promotions. For instance, a special sale page may have the category hierarchy: "pageCategories" : ["Sales > 2017 Black Friday Deals"].
#page_categories=
def page_categories=(value) -> ::Array<::String>
-
value (::Array<::String>) — The categories associated with a category page. Required for category
navigation queries to achieve good search quality. The format should be
the same as
UserEvent.page_categories;
To represent full path of category, use '>' sign to separate different hierarchies. If '>' is part of the category name, please replace it with other character(s).
Category pages include special pages such as sales or promotions. For instance, a special sale page may have the category hierarchy: "pageCategories" : ["Sales > 2017 Black Friday Deals"].
-
(::Array<::String>) — The categories associated with a category page. Required for category
navigation queries to achieve good search quality. The format should be
the same as
UserEvent.page_categories;
To represent full path of category, use '>' sign to separate different hierarchies. If '>' is part of the category name, please replace it with other character(s).
Category pages include special pages such as sales or promotions. For instance, a special sale page may have the category hierarchy: "pageCategories" : ["Sales > 2017 Black Friday Deals"].
#page_size
def page_size() -> ::Integer
-
(::Integer) — Maximum number of Products to return. If
unspecified, defaults to a reasonable value. The maximum allowed value is
- Values above 120 will be coerced to 120.
If this field is negative, an INVALID_ARGUMENT is returned.
#page_size=
def page_size=(value) -> ::Integer
-
value (::Integer) — Maximum number of Products to return. If
unspecified, defaults to a reasonable value. The maximum allowed value is
- Values above 120 will be coerced to 120.
If this field is negative, an INVALID_ARGUMENT is returned.
-
(::Integer) — Maximum number of Products to return. If
unspecified, defaults to a reasonable value. The maximum allowed value is
- Values above 120 will be coerced to 120.
If this field is negative, an INVALID_ARGUMENT is returned.
#page_token
def page_token() -> ::String
-
(::String) — A page token
SearchResponse.next_page_token,
received from a previous
SearchService.Search call.
Provide this to retrieve the subsequent page.
When paginating, all other parameters provided to SearchService.Search must match the call that provided the page token. Otherwise, an INVALID_ARGUMENT error is returned.
#page_token=
def page_token=(value) -> ::String
-
value (::String) — A page token
SearchResponse.next_page_token,
received from a previous
SearchService.Search call.
Provide this to retrieve the subsequent page.
When paginating, all other parameters provided to SearchService.Search must match the call that provided the page token. Otherwise, an INVALID_ARGUMENT error is returned.
-
(::String) — A page token
SearchResponse.next_page_token,
received from a previous
SearchService.Search call.
Provide this to retrieve the subsequent page.
When paginating, all other parameters provided to SearchService.Search must match the call that provided the page token. Otherwise, an INVALID_ARGUMENT error is returned.
#personalization_spec
def personalization_spec() -> ::Google::Cloud::Retail::V2::SearchRequest::PersonalizationSpec
- (::Google::Cloud::Retail::V2::SearchRequest::PersonalizationSpec) — The specification for personalization.
#personalization_spec=
def personalization_spec=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::PersonalizationSpec
- value (::Google::Cloud::Retail::V2::SearchRequest::PersonalizationSpec) — The specification for personalization.
- (::Google::Cloud::Retail::V2::SearchRequest::PersonalizationSpec) — The specification for personalization.
#placement
def placement() -> ::String
-
(::String) — Required. The resource name of the search engine placement, such as
projects/*/locations/global/catalogs/default_catalog/placements/default_search
. This field is used to identify the serving configuration name and the set of models that will be used to make the search.
#placement=
def placement=(value) -> ::String
-
value (::String) — Required. The resource name of the search engine placement, such as
projects/*/locations/global/catalogs/default_catalog/placements/default_search
. This field is used to identify the serving configuration name and the set of models that will be used to make the search.
-
(::String) — Required. The resource name of the search engine placement, such as
projects/*/locations/global/catalogs/default_catalog/placements/default_search
. This field is used to identify the serving configuration name and the set of models that will be used to make the search.
#query
def query() -> ::String
-
(::String) — Raw search query.
If this field is empty, the request is considered a category browsing request and returned results are based on filter and page_categories.
#query=
def query=(value) -> ::String
-
value (::String) — Raw search query.
If this field is empty, the request is considered a category browsing request and returned results are based on filter and page_categories.
-
(::String) — Raw search query.
If this field is empty, the request is considered a category browsing request and returned results are based on filter and page_categories.
#query_expansion_spec
def query_expansion_spec() -> ::Google::Cloud::Retail::V2::SearchRequest::QueryExpansionSpec
- (::Google::Cloud::Retail::V2::SearchRequest::QueryExpansionSpec) — The query expansion specification that specifies the conditions under which query expansion will occur. See more details at this user guide.
#query_expansion_spec=
def query_expansion_spec=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::QueryExpansionSpec
- value (::Google::Cloud::Retail::V2::SearchRequest::QueryExpansionSpec) — The query expansion specification that specifies the conditions under which query expansion will occur. See more details at this user guide.
- (::Google::Cloud::Retail::V2::SearchRequest::QueryExpansionSpec) — The query expansion specification that specifies the conditions under which query expansion will occur. See more details at this user guide.
#search_mode
def search_mode() -> ::Google::Cloud::Retail::V2::SearchRequest::SearchMode
- (::Google::Cloud::Retail::V2::SearchRequest::SearchMode) — The search mode of the search request. If not specified, a single search request triggers both product search and faceted search.
#search_mode=
def search_mode=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::SearchMode
- value (::Google::Cloud::Retail::V2::SearchRequest::SearchMode) — The search mode of the search request. If not specified, a single search request triggers both product search and faceted search.
- (::Google::Cloud::Retail::V2::SearchRequest::SearchMode) — The search mode of the search request. If not specified, a single search request triggers both product search and faceted search.
#spell_correction_spec
def spell_correction_spec() -> ::Google::Cloud::Retail::V2::SearchRequest::SpellCorrectionSpec
- (::Google::Cloud::Retail::V2::SearchRequest::SpellCorrectionSpec) — The spell correction specification that specifies the mode under which spell correction will take effect.
#spell_correction_spec=
def spell_correction_spec=(value) -> ::Google::Cloud::Retail::V2::SearchRequest::SpellCorrectionSpec
- value (::Google::Cloud::Retail::V2::SearchRequest::SpellCorrectionSpec) — The spell correction specification that specifies the mode under which spell correction will take effect.
- (::Google::Cloud::Retail::V2::SearchRequest::SpellCorrectionSpec) — The spell correction specification that specifies the mode under which spell correction will take effect.
#user_info
def user_info() -> ::Google::Cloud::Retail::V2::UserInfo
- (::Google::Cloud::Retail::V2::UserInfo) — User information.
#user_info=
def user_info=(value) -> ::Google::Cloud::Retail::V2::UserInfo
- value (::Google::Cloud::Retail::V2::UserInfo) — User information.
- (::Google::Cloud::Retail::V2::UserInfo) — User information.
#variant_rollup_keys
def variant_rollup_keys() -> ::Array<::String>
-
(::Array<::String>) — The keys to fetch and rollup the matching
variant
Products attributes,
FulfillmentInfo or
LocalInventorys attributes. The
attributes from all the matching
variant
Products or
LocalInventorys are merged and
de-duplicated. Notice that rollup attributes will lead to extra query
latency. Maximum number of keys is 30.
For FulfillmentInfo, a fulfillment type and a fulfillment ID must be provided in the format of "fulfillmentType.fulfillmentId". E.g., in "pickupInStore.store123", "pickupInStore" is fulfillment type and "store123" is the store ID.
Supported keys are:
- colorFamilies
- price
- originalPrice
- discount
- variantId
- inventory(place_id,price)
- inventory(place_id,original_price)
- inventory(place_id,attributes.key), where key is any key in the Product.local_inventories.attributes map.
- attributes.key, where key is any key in the Product.attributes map.
- pickupInStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "pickup-in-store".
- shipToStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "ship-to-store".
- sameDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "same-day-delivery".
- nextDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "next-day-delivery".
- customFulfillment1.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-1".
- customFulfillment2.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-2".
- customFulfillment3.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-3".
- customFulfillment4.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-4".
- customFulfillment5.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-5".
If this field is set to an invalid value other than these, an INVALID_ARGUMENT error is returned.
#variant_rollup_keys=
def variant_rollup_keys=(value) -> ::Array<::String>
-
value (::Array<::String>) — The keys to fetch and rollup the matching
variant
Products attributes,
FulfillmentInfo or
LocalInventorys attributes. The
attributes from all the matching
variant
Products or
LocalInventorys are merged and
de-duplicated. Notice that rollup attributes will lead to extra query
latency. Maximum number of keys is 30.
For FulfillmentInfo, a fulfillment type and a fulfillment ID must be provided in the format of "fulfillmentType.fulfillmentId". E.g., in "pickupInStore.store123", "pickupInStore" is fulfillment type and "store123" is the store ID.
Supported keys are:
- colorFamilies
- price
- originalPrice
- discount
- variantId
- inventory(place_id,price)
- inventory(place_id,original_price)
- inventory(place_id,attributes.key), where key is any key in the Product.local_inventories.attributes map.
- attributes.key, where key is any key in the Product.attributes map.
- pickupInStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "pickup-in-store".
- shipToStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "ship-to-store".
- sameDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "same-day-delivery".
- nextDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "next-day-delivery".
- customFulfillment1.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-1".
- customFulfillment2.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-2".
- customFulfillment3.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-3".
- customFulfillment4.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-4".
- customFulfillment5.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-5".
If this field is set to an invalid value other than these, an INVALID_ARGUMENT error is returned.
-
(::Array<::String>) — The keys to fetch and rollup the matching
variant
Products attributes,
FulfillmentInfo or
LocalInventorys attributes. The
attributes from all the matching
variant
Products or
LocalInventorys are merged and
de-duplicated. Notice that rollup attributes will lead to extra query
latency. Maximum number of keys is 30.
For FulfillmentInfo, a fulfillment type and a fulfillment ID must be provided in the format of "fulfillmentType.fulfillmentId". E.g., in "pickupInStore.store123", "pickupInStore" is fulfillment type and "store123" is the store ID.
Supported keys are:
- colorFamilies
- price
- originalPrice
- discount
- variantId
- inventory(place_id,price)
- inventory(place_id,original_price)
- inventory(place_id,attributes.key), where key is any key in the Product.local_inventories.attributes map.
- attributes.key, where key is any key in the Product.attributes map.
- pickupInStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "pickup-in-store".
- shipToStore.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "ship-to-store".
- sameDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "same-day-delivery".
- nextDayDelivery.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "next-day-delivery".
- customFulfillment1.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-1".
- customFulfillment2.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-2".
- customFulfillment3.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-3".
- customFulfillment4.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-4".
- customFulfillment5.id, where id is any FulfillmentInfo.place_ids for FulfillmentInfo.type "custom-type-5".
If this field is set to an invalid value other than these, an INVALID_ARGUMENT error is returned.
#visitor_id
def visitor_id() -> ::String
-
(::String) — Required. A unique identifier for tracking visitors. For example, this
could be implemented with an HTTP cookie, which should be able to uniquely
identify a visitor on a single device. This unique identifier should not
change if the visitor logs in or out of the website.
This should be the same identifier as UserEvent.visitor_id.
The field must be a UTF-8 encoded string with a length limit of 128 characters. Otherwise, an INVALID_ARGUMENT error is returned.
#visitor_id=
def visitor_id=(value) -> ::String
-
value (::String) — Required. A unique identifier for tracking visitors. For example, this
could be implemented with an HTTP cookie, which should be able to uniquely
identify a visitor on a single device. This unique identifier should not
change if the visitor logs in or out of the website.
This should be the same identifier as UserEvent.visitor_id.
The field must be a UTF-8 encoded string with a length limit of 128 characters. Otherwise, an INVALID_ARGUMENT error is returned.
-
(::String) — Required. A unique identifier for tracking visitors. For example, this
could be implemented with an HTTP cookie, which should be able to uniquely
identify a visitor on a single device. This unique identifier should not
change if the visitor logs in or out of the website.
This should be the same identifier as UserEvent.visitor_id.
The field must be a UTF-8 encoded string with a length limit of 128 characters. Otherwise, an INVALID_ARGUMENT error is returned.