def processExited(reason):
    """
        Called when the child process exits.

        @type reason: L{twisted.python.failure.Failure}
        @param reason: A failure giving the reason the child process
            terminated.  The type of exception for this failure is either
            L{twisted.internet.error.ProcessDone} or
            L{twisted.internet.error.ProcessTerminated}.

        @since: 8.2
        """
