code: def _parse_normalization(normalization):
          
          parsed_normalization = None
  
          if isinstance(normalization, dict):
              if len(normalization.keys()) == 1:
                  items = list(normalization.items())[0]
                  if len(items) == 2: # Two elements tuple
                      # Convert to string if no normalization options
                      if items[1] and isinstance(items[1], dict):
                          parsed_normalization = items
                      else:
                          parsed_normalization = items[0]
          elif isinstance(normalization, STR_TYPE):
              parsed_normalization = normalization
  
          return parsed_normalization
docs: Parse a normalization item.
  
          Transform dicts into a tuple containing the normalization
          options. If a string is found, the actual value is used.
  
          Args:
              normalization: Normalization to parse.
  
          Returns:
              Tuple or string containing the parsed normalization.