code: def fetch_uri_contents(self, uri: str) -> URI:
          
          address, pkg_name, pkg_version = parse_registry_uri(uri)
          self.w3.enable_unstable_package_management_api()
          self.w3.pm.set_registry(address)
          _, _, manifest_uri = self.w3.pm.get_release_data(pkg_name, pkg_version)
          return manifest_uri
docs: Return content-addressed URI stored at registry URI.