docs: def _pad_input(incoming):
      """Avoid IndexError and KeyError by ignoring un-related fields.
  
      Example: '{0}{autored}' becomes '{{0}}{autored}'.
  
      Positional arguments:
      incoming -- the input unicode value.
  
      Returns:
      Padded unicode value.
      """
      incoming_expanded = incoming.replace('{', '{{').replace('}', '}}')
      for key in _BASE_CODES:
          before, after = '{{%s}}' % key, '{%s}' % key
          if before in incoming_expanded:
              incoming_expanded = incoming_expanded.replace(before, after)
      return incoming_expanded