send method
Sends a message to the JavaScript receiver with a commandName
.
Implementation
void send(String commandName,
{Map<String, dynamic>? data, SendMessageCallback? callback}) {
String callbackId = _addSendMessageCallback(commandName, callback);
_requests
.add(_Request(name: commandName, callbackId: callbackId, data: data));
_waitForReadyAndSendRequests();
}