parameters: (formats)
return_statement: return None
docstring: Returns the first format from the 'format' list that is unknown.
  
      If all formats are known, returns None
docstring_summary: Returns the first format from the 'format' list that is unknown.
docstring_tokens: Returns the first format from the format list that is unknown .
function: def check_archive_formats(formats):
      """Returns the first format from the 'format' list that is unknown.
  
      If all formats are known, returns None
      """
      for format in formats:
          if format not in ARCHIVE_FORMATS:
              return format
      return None
function_tokens: def check_archive_formats ( formats ) : for format in formats : if format not in ARCHIVE_FORMATS : return format return None