docs: def get_artifact_metadata(self, package_name):
          """
          Return metadata of the artifacts built through this registry.
          """
  
          filename = self.metadata.get(package_name)
          if not filename or not exists(filename):
              return {}
          with open(filename, encoding='utf8') as fd:
              contents = fd.read()
  
          try:
              is_json_compat(contents)
          except ValueError:
              logger.info("artifact metadata file '%s' is invalid", filename)
              return {}
  
          return json.loads(contents)