'Disable a plugin with dependents.'

def test_disable_dependendents(self):

    p = PluginManager(None)
    events = []
    A.plugin_end = (lambda s: events.append('end_a'))
    B.plugin_end = (lambda s: events.append('end_b'))
    F.plugin_end = (lambda s: events.append('end_f'))
    p.enable('f')
    p.disable('a')
    self.assertEqual(len(p), 1, 'Wrong    number    of    enabled    plugins.')
    self.assertTrue(('end_f' in events), 'Dependent    F    not    disabled.')
    self.assertTrue(('end_a' in events), 'Plugin    A    not    disabled.')
