Thin wrapper around a system-level process. Most closely resembles Python's subprocess.Popen class.
Returns the return code of the process, or null if unfinished.
Blocks until poll() would return a non-null return code.
Signal to the Process that it should terminate. This may be done "softly" for a given time period.
Terminate the Process immediately.
First attempts cancel() several times and finally resorts to kill to force the process to shutdown cleanly. This method doesn't return any value or throw an exception so that it can be called oneway.
Add a callback for end-of-life events
Remove a callback for end-of-life events