defaultBinaryMessenger property Null safety
The default instance of BinaryMessenger.
This is used to send messages from the application to the platform, and keeps track of which handlers have been registered on each channel so it may dispatch incoming messages to the registered handler.
The default implementation returns a BinaryMessenger that delivers the messages in the same order in which they are sent.
@override TestDefaultBinaryMessenger get defaultBinaryMessenger => super.defaultBinaryMessenger as TestDefaultBinaryMessenger;