OptionalcatchingOptionalerrorThe matrix error if state=ERROR.
OptionalfromOptionalnextThe 'next_batch' result from /sync, which
will become the 'since' token for the next call to /sync. Only present if
state=PREPARED</code> or <code>state=SYNCING.
OptionaloldThe 'since' token passed to /sync.
null for the first successful sync since this client was
started. Only present if state=PREPARED or
state=SYNCING.
True if we are working our way through a backlog of events after connecting. Only present if
state=SYNCING.