code: def get_default_value(self, check):
          
          fun_name, fun_args, fun_kwargs, default = self._parse_with_caching(check)
          if default is None:
              raise KeyError('Check "%s" has no default value.' % check)
          value = self._handle_none(default)
          if value is None:
              return value
          return self._check_value(value, fun_name, fun_args, fun_kwargs)
docs: Given a check, return the default value for the check
          (converted to the right type).
  
          If the check doesn't specify a default value then a
          ``KeyError`` will be raised.