code: def field_caps(self, index=None, body=None, params=None):
          
          return self.transport.perform_request(
              "GET", _make_path(index, "_field_caps"), params=params, body=body
          )
docs: The field capabilities API allows to retrieve the capabilities of fields among multiple indices.
          `<http://www.elastic.co/guide/en/elasticsearch/reference/current/search-field-caps.html>`_
  
          :arg index: A list of index names, or a string containing a
              comma-separated list of index names; use `_all` or the empty string
              to perform the operation on all indices
          :arg body: Field json objects containing an array of field names
          :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 fields: A comma-separated list of field names
          :arg ignore_unavailable: Whether specified concrete indices should be
              ignored when unavailable (missing or closed)