code: def remove(cls, module_name):
          
          module_guards = cls._guards.get(module_name, False)
          if module_guards:
              module_guards.pop()
              cls._num_entries -= 1
              if cls._num_entries < 1:
                  if cls._num_entries < 0:
                      raise Exception(
                          'Bug: ImportGuardHook._num_entries became negative!'
                      )
                  cls._uninstall()
docs: drop a previously created guard on ``module_name``
          if the module is not guarded, then this is a no-op.