code: def __insert_wrapper(func):
          
          def check_func(self, key, new_item, instance=0):
              if key not in self.keys():
                  raise KeyError("%s not a key in label" % (key))
              if not isinstance(new_item, (list, OrderedMultiDict)):
                  raise TypeError("The new item must be a list or PVLModule")
              if isinstance(new_item, OrderedMultiDict):
                  new_item = list(new_item)
              return func(self, key, new_item, instance)
          return check_func
docs: Make sure the arguments given to the insert methods are correct