docs: def inflate_nd_checker(identifier, definition):
          """
          Inflate a no-data checker from a basic definition.
  
          Args:
              identifier (str): the no-data checker identifier / name.
              definition (bool/dict): a boolean acting as "passes" or a full
                  dict definition with "passes" and "allow_failure".
  
          Returns:
              Checker: a checker instance.
  
          Raises:
              ValueError: when the definition type is not bool or dict.
          """
          if isinstance(definition, bool):
              return Checker(name=identifier, passes=definition)
          elif isinstance(definition, dict):
              return Checker(definition.pop('name', identifier), **definition)
          else:
              raise ValueError('%s type is not supported for no-data checkers, '
                               'use bool or dict' % type(definition))