MongoDB\Driver\Session::advanceClusterTime — Advances the cluster time for this session
Advances the cluster time for this session. If the cluster time is less than or equal to the session's current cluster time, this function is a no-op.
By using this method in conjunction with MongoDB\Driver\Session::advanceOperationTime() to copy the cluster and operation times from another session, you can ensure that operations in this session are causally consistent with the last operation in the other session.
The cluster time is a document containing a logical timestamp and server signature. Typically, this value will be obtained by calling MongoDB\Driver\Session::getClusterTime() on another session object.