code: def unregister(cls, plugin):
          
          plugs = getattr(cls, '_%s__plugins' % cls.__name__, {})
          try:
              plugs.pop(plugin.name())
          except AttributeError:
              pass
          except ValueError:
              pass
docs: Unregisters the given plugin from the system based on its name.
          
          :param      plugin | <Plugin>