readTime property
read / write
The time at which the document was read. This may be monotonically
increasing; in this case, the previous documents in the result stream are
guaranteed not to have changed between their read_time
and this one. If
the query returns no results, a response with read_time
and no
document
will be sent, and this represents the time at which the query
was run.
Implementation
core.String readTime;