def test_processes(self):
        """
        Accessing L{ProcessMonitor.processes} results in deprecation warning

        Even when there are no processes, and thus no process is converted
        to a tuple, accessing the L{ProcessMonitor.processes} property
        should generate its own DeprecationWarning.
        """
        myProcesses = self.pm.processes
        self.assertEquals(myProcesses, {})
        warnings = self.flushWarnings()
        first = warnings.pop(0)
        self.assertIs(first['category'], DeprecationWarning)
        self.assertEquals(warnings, [])

        Accessing L{ProcessMonitor.processes} results in deprecation warning

        Even when there are no processes, and thus no process is converted
        to a tuple, accessing the L{ProcessMonitor.processes} property
        should generate its own DeprecationWarning.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/runner/test/test_procmon.py