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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def Runs(self):
 """Return all the run names in the `EventMultiplexer`. Returns: ``` {runName: { scalarValues: [tagA, tagB, tagC], graph: true, meta_graph: true}} ``` """

    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}