code: def contains_value(self, *values):
          
          self._check_dict_like(self.val, check_getitem=False)
          if len(values) == 0:
              raise ValueError('one or more value args must be given')
          missing = []
          for v in values:
              if v not in self.val.values():
                  missing.append(v)
          if missing:
              self._err('Expected <%s> to contain values %s, but did not contain %s.' % (self.val, self._fmt_items(values), self._fmt_items(missing)))
          return self
docs: Asserts that val is a dict and contains the given value or values.