psubscribe method
PSUBSCRIBE command (pattern subscribe)
Implementation
@override
Stream<V> psubscribe(String pattern) {
_connection.sendCommand(Resp(['PSUBSCRIBE', pattern]));
return _connection.stream
.map((event) => event?.arrayValue)
.where((event) => event != null)
.map((event) => event!)
.where((e) => e.length == 4) // length == 3 is subscribed notification
.map((event) => valueCodec.decode(event.last));
}