anchor.diff:  calc_delay_max(#fitting_details{arg = {rct, _ReduceFun, ReduceArg}}) ->
       Props = case ReduceArg of
                   L when is_list(L) -> L;         % May or may not be a proplist
  +                {struct, L} -> delay_props_from_json(L);
                   _                 -> []
               end,
       AppMax = app_helper:get_env(riak_kv, mapred_reduce_phase_batch_size, 20),
  
positive.code:             proplists:get_value(reduce_phase_batch_size,
                                  Props, AppMax)
      end.
  
negative.code: %% ```
  %% X = Fun([C,B,A], Arg)
  %% '''
  %%
  %% To use `reduce_phase_only_1' and `reduce_phase_batch_size' over the
  %% HTTP interface, specify a JSON structure as the function's
  %% argument, as in:
  %% ```
  %% {...,"query":[...,{"reduce":{...,"arg":{"reduce_phase_batch_size":100}}}]}
  %% '''
  %% Or:
  %% ```
  %% {...,"query":[...,{"reduce":{...,"arg":{"reduce_phase_only1":true}}}]}
  %% '''
  %% The HTTP interface will translate that argument into a mochijson2
  %% structure (e.g. `{struct, [{<<"reduce_phase_only_1">>, true}]}'),
  %% which this fitting will understand.  This also provides a safe way
  %% to pass these arguments when using a reduce phase implemented in
  %% Javascript over the Protocol Buffer or native interfaces.
  %% Mochijson2 conversion will fail on the bare proplist, but will
  %% succeed at encoding this form.
  %%
  %% The exception to the batching controls is handoff.  Whenever a
  %% worker receives handoff from another worker, it immediately reduces
  