code: def Runs(self):
      
      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_name: accumulator.Tags() for run_name, accumulator in items}
docs: Return all the run names in the `EventMultiplexer`.
  
      Returns:
      ```
        {runName: { scalarValues: [tagA, tagB, tagC],
                    graph: true, meta_graph: true}}
      ```