code: def _normalized_keys(self, section, items):
          # type: (str, Iterable[Tuple[str, Any]]) -> Dict[str, Any]
          
          normalized = {}
          for name, val in items:
              key = section + "." + _normalize_name(name)
              normalized[key] = val
          return normalized
docs: Normalizes items to construct a dictionary with normalized keys.
  
          This routine is where the names become keys and are made the same
          regardless of source - configuration files or environment.