emit method
Emits a change if the map has been modified since the last emit (or since it was initialized).
To emit a change but prevent a parent EmitterContainer from emitting a change, set quiet to true.
Implementation
emit({bool quiet = false}) {
assert(!isDisposed);
if (_dirty && !quiet)
addChangeToStream(
emitDetailedChanges ? MapChange(_changes) : MapChange.any());
else if (_dirty)
addChangeToStream(emitDetailedChanges
? MapChange(_changes, quiet: true)
: MapChange.any(quiet: true));
_changes.clear();
_dirty = false;
}