def test_removeProcess(self):
        """
        L{ProcessMonitor.removeProcess} removes the process from the public
        processes list.
        """
        self.pm.startService()
        self.pm.addProcess("foo", ["foo"])
        self.assertEqual(len(self.pm.processes), 1)
        self.pm.removeProcess("foo")
        self.assertEqual(len(self.pm.processes), 0)

        L{ProcessMonitor.removeProcess} removes the process from the public
        processes list.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/runner/test/test_procmon.py