code: def drop_streams(streams, kdims, keys):
      
      stream_params = stream_parameters(streams)
      inds, dims = zip(*[(ind, kdim) for ind, kdim in enumerate(kdims)
                         if kdim not in stream_params])
      get = operator.itemgetter(*inds) # itemgetter used for performance
      keys = (get(k) for k in keys)
      return dims, ([wrap_tuple(k) for k in keys] if len(inds) == 1 else list(keys))
docs: Drop any dimensioned streams from the keys and kdims.