code: def parse_field(field: str) -> Tuple[str, Optional[str]]:
      
      _field = field.split('.')
      _field = [f.strip() for f in _field]
      if len(_field) == 1 and _field[0]:
          return _field[0], None
      elif len(_field) == 2 and _field[0] and _field[1]:
          return _field[0], _field[1]
      raise QueryParserException('Query field must be either a single value,'
                                 'possibly with single underscores, '
                                 'or a prefix double underscore field. '
                                 'Received `{}`'.format(field))
docs: Parses fields with underscores, and return field and suffix.
  
      Example:
          foo => foo, None
          metric.foo => metric, foo