code: def _dist_kw_arg(self, k):
          
          if self._dist_kw_args is not None:
              return {
                  key:self._dist_kw_args[key][k,:]
                  for key in self._dist_kw_args.keys()
              }
          else:
              return {}
docs: Returns a dictionary of keyword arguments
          for the k'th distribution.
  
          :param int k: Index of the distribution in question.
          :rtype: ``dict``