added pg_setting_export_example_enhanced.py and new method list_vpgs_from_exported_settings in vpgs.py

venv/lib/python3.9/site-packages/pip/_internal/distributions/installed.py

@@ -0,0 +1,22 @@
+from typing import Optional
+
+from pip._vendor.pkg_resources import Distribution
+
+from pip._internal.distributions.base import AbstractDistribution
+from pip._internal.index.package_finder import PackageFinder
+
+
+class InstalledDistribution(AbstractDistribution):
+    """Represents an installed package.
+
+    This does not need any preparation as the required information has already
+    been computed.
+    """
+
+    def get_pkg_resources_distribution(self) -> Optional[Distribution]:
+        return self.req.satisfied_by
+
+    def prepare_distribution_metadata(
+        self, finder: PackageFinder, build_isolation: bool
+    ) -> None:
+        pass