def _parse_attr(self, value, package_dir, root_dir: _Path):
        """Represents value as a module attribute.

        Examples:
            attr: package.attr
            attr: package.module.attr

        :param str value:
        :rtype: str
        """
        attr_directive = 'attr:'
        if not value.startswith(attr_directive):
            return value

        attr_desc = value.replace(attr_directive, '')

        # Make sure package_dir is populated correctly, so `attr:` directives can work
        package_dir.update(self.ensure_discovered.package_dir)
        return expand.read_attr(attr_desc, package_dir, root_dir)
Represents value as a module attribute.

        Examples:
            attr: package.attr
            attr: package.module.attr

        :param str value:
        :rtype: str
        
product/gradle-plugin/src/main/python/setuptools/config/setupcfg.py