SendPort class Null safety
Sends messages to its ReceivePorts.
SendPorts can be transmitted to other isolates, and they preserve equality when sent.
Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
Object? message) → void
Sends an asynchronous
messagethrough this send port, to its corresponding ReceivePort.
) → String
A string representation of this object.