Automatic spell correction built by the Search API. Search will
be based on the corrected query if found.
SuggestionOnly
Search API tries to find a spelling suggestion. If a suggestion is
found, it is put in the
[SearchResponse.corrected_query][google.cloud.discoveryengine.v1beta.SearchResponse.corrected_query].
The spelling suggestion won't be used as the search query.
Unspecified
Unspecified spell correction mode. In this case, server behavior
defaults to
[Mode.AUTO][google.cloud.discoveryengine.v1beta.SearchRequest.SpellCorrectionSpec.Mode.AUTO].