code: def PluginAssets(self, plugin_name):
      
      with self._accumulators_mutex:
        # To avoid nested locks, we construct a copy of the run-accumulator map
        items = list(six.iteritems(self._accumulators))
  
      return {run: accum.PluginAssets(plugin_name) for run, accum in items}
docs: Get index of runs and assets for a given plugin.
  
      Args:
        plugin_name: Name of the plugin we are checking for.
  
      Returns:
        A dictionary that maps from run_name to a list of plugin
          assets for that run.