def METHOD_NAME(self, arg=''):
    """
    This method must return statements or declarations suitable to define
    the current style for subsequent highlighted text (e.g. CSS classes
    in the `HTMLFormatter`).
    The optional argument `arg` can be used to modify the generation and
    is formatter dependent (it is standardized because it can be given on
    the command line).
    This method is called by the ``-S`` :doc:`command-line option <cmdline>`,
    the `arg` is then given by the ``-a`` option.
    """
    return ''