docs: def list_benchmarks(self,
              index    = None,
              doc_type = None,
              params   = {},
              cb       = None,
              **kwargs
          ):
          """
          View the progress of long-running benchmarks.
          `<http://www.elasticsearch.org/guide/en/elasticsearch/reference/master/search-benchmark.html>`_
          :arg index: A comma-separated list of index names; use `_all` or empty
              string to perform the operation on all indices
          :arg doc_type: The name of the document type
          """
  
          url = self.mk_url(*[index, doc_type, '_bench'], **params)
  
          self.client.fetch(
              self.mk_req(url, method='GET', **kwargs),
              callback = callback
          )