code: def _calculateEncodingKey(comparator):
      
      encodingName = None
      for k, v in list(_encodings.items()):
          if v == comparator:
              encodingName = k
              break
      return encodingName
docs: Gets the first key of all available encodings where the corresponding
      value matches the comparator.
  
      Args:
          comparator (string): A view name for an encoding.
  
      Returns:
          str: A key for a specific encoding used by python.