void onMessage(@Nullable T message, @NonNull BasicMessageChannel.Reply<T> reply)Handles the specified message received from Flutter.
Handler implementations must reply to all incoming messages, by submitting a single reply message to the given
BasicMessageChannel.Reply. Failure to do so will result in lingering Flutter reply handlers. The reply may be submitted asynchronously and invoked on any thread.
Any uncaught exception thrown by this method, or the preceding message decoding, will be caught by the channel implementation and logged, and a null reply message will be sent back to Flutter.
Any uncaught exception thrown during encoding a reply message submitted to the
BasicMessageChannel.Replyis treated similarly: the exception is logged, and a null reply is sent to Flutter.
message- the message, possibly null.
BasicMessageChannel.Replyfor sending a single message reply back to Flutter.