code: def flush(self, index=None, params=None):
          
          return self.transport.perform_request(
              "POST", _make_path(index, "_flush"), params=params
          )
docs: Explicitly flush one or more indices.
          `<http://www.elastic.co/guide/en/elasticsearch/reference/current/indices-flush.html>`_
  
          :arg index: A comma-separated list of index names; use `_all` or empty
              string for 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 force: Whether a flush should be forced even if it is not
              necessarily needed ie. if no changes will be committed to the index.
              This is useful if transaction log IDs should be incremented even if
              no uncommitted changes are present. (This setting can be considered
              as internal)
          :arg ignore_unavailable: Whether specified concrete indices should be
              ignored when unavailable (missing or closed)
          :arg wait_if_ongoing: If set to true the flush operation will block
              until the flush can be executed if another flush operation is
              already executing. The default is true. If set to false the flush
              will be skipped iff if another flush operation is already running.