insertId property
Optional. A unique identifier for the log entry. If you provide a value,
then Logging considers other log entries in the same project, with the same
timestamp, and with the same insert_id to be duplicates which are
removed in a single query result. However, there are no guarantees of
de-duplication in the export of logs.
If the insert_id is omitted when writing a log entry, the Logging API
assigns its own unique identifier in this field.
In queries, the insert_id is also used to order log entries that have
the same log_name and timestamp values.
Implementation
final String insertId;