fromMessage method
Implementation
Map<String, dynamic>? fromMessage(MessageEnvelope? message) {
if (message == null) return null;
var data = message.message;
if (_serializeEnvelope) {
message.sent_time = DateTime.now();
data = json.encode(message.toJSON());
}
return {'topic': getName().isNotEmpty ? getName() : _topic, 'data': data};
}