@classmethod
def importer(cls, importer_name=None):
    """
        Get an importer instance to instantiate a component from file.

        :param importer_name: registered name of importer to use, see
                              :meth:`register_importer() <cqparts.codec.register_importer>`
                              for more information.
        :type importer_name: :class:`str`

        For example, to get an importer to instantiate a :class:`Part` from a
        ``STEP`` file:

        .. doctest::

            >>> from cqparts import Part
            >>> step_importer = Part.importer('step')

            >>> # then each importer will behave differently
            >>> my_part = step_importer('my_file.step')  # doctest: +SKIP

        To learn more: :ref:`parts_import-export`
        """
    from .codec import get_importer
    return get_importer(cls, importer_name)
