Pass options through to this plugin.

def parse_options(cls, options):
    """Pass options through to this plugin."""
    cls.ignore_decorators = options.ignore_decorators
    cls.exclude_from_doctest = options.exclude_from_doctest
    if not isinstance(cls.exclude_from_doctest, list):
      cls.exclude_from_doctest = [cls.exclude_from_doctest]