def METHOD_NAME(self):
    """Extend $GEM_PATH in module file."""
    txt = super(RubyGem, self).METHOD_NAME()
    # for stand-alone Ruby gem installs, $GEM_PATH needs to be updated
    if not self.is_extension or self.master.name != 'Ruby':
        txt += self.module_generator.prepend_paths('GEM_PATH', [''])
    return txt