code: def state(self, metric=None, index=None, params=None):
          
          if index and not metric:
              metric = '_all'
          return self.transport.perform_request('GET', _make_path('_cluster',
              'state', metric, index), params=params)
docs: Get a comprehensive state information of the whole cluster.
          `<http://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-state.html>`_
  
          :arg metric: Limit the information returned to the specified metrics
          :arg index: A comma-separated list of index names; use `_all` or empty
              string to perform the operation on all indices
          :arg allow_no_indices: Whether to ignore if a wildcard indices
              expression resolves into no concrete indices. (This includes `_all`
              string or when no indices have been specified)
          :arg expand_wildcards: Whether to expand wildcard expression to concrete
              indices that are open, closed or both., default 'open', valid
              choices are: 'open', 'closed', 'none', 'all'
          :arg flat_settings: Return settings in flat format (default: false)
          :arg ignore_unavailable: Whether specified concrete indices should be
              ignored when unavailable (missing or closed)
          :arg local: Return local information, do not retrieve the state from
              master node (default: false)
          :arg master_timeout: Specify timeout for connection to master