str
Required. The subscription from which messages should be
pulled. Format is
``projects/{project}/subscriptions/{sub}``.
return_immediately
bool
Optional. If this field set to true, the system will respond
immediately even if it there are no messages available to
return in the ``Pull`` response. Otherwise, the system may
wait (for a bounded amount of time) until at least one
message is available, rather than returning no messages.
Warning: setting this field to ``true`` is discouraged
because it adversely impacts the performance of ``Pull``
operations. We recommend that users do not set this field.
max_messages
int
Required. The maximum number of messages to
return for this request. Must be a positive
integer. The Pub/Sub system may return fewer
than the number specified.