addLiteral method
Implementation
void addLiteral(String key, void Function(Literal node) listener) {
_forLiteral.add(_Subscription(listener, _getTimer(key), Zone.current));
}
void addLiteral(String key, void Function(Literal node) listener) {
_forLiteral.add(_Subscription(listener, _getTimer(key), Zone.current));
}