code: def up_to(self, key):
          '''Gets the recently inserted values up to a key'''
          for okey, ovalue in reversed(self.history):
              if okey == key:
                  break
              else:
                  yield ovaluf up_to(self, key):
          '''Gets the recently inserted values up to a key'''
          for okey, ovalue in reversed(self.history):
              if okey == key:
                  break
              else:
                  yield ovalue
docs: Gets the recently inserted values up to a key