anchor.diff:  make_options(Prev, Ctx) ->
       NewOpts0 = [{rw, Ctx#ctx.rw}, {r, Ctx#ctx.r}, {w, Ctx#ctx.w},
                   {pr, Ctx#ctx.pr}, {pw, Ctx#ctx.pw}, {dw, Ctx#ctx.dw},
  -                {timeout, Ctx#ctx.timeout}],
  +                {timeout, Ctx#ctx.timeout}, {asis, Ctx#ctx.asis}],
       NewOpts = [ {Opt, Val} || {Opt, Val} <- NewOpts0,
                                 Val /= undefined, Val /= default ],
       Prev ++ NewOpts.
  
positive.code:               pw,           %% integer() - number of primary nodes required in preflist on write
                basic_quorum, %% boolean() - whether to use basic_quorum
                notfound_ok,  %% boolean() - whether to treat notfounds as successes
                prefix,       %% string() - prefix for resource uris
                riak,         %% local | {node(), atom()} - params for riak client
                doc,          %% {ok, riak_object()}|{error, term()} - the object found
  
negative.code:     lists:foldl(fun malformed_boolean_param/2,
                  Res,
                  [{#ctx.basic_quorum, "basic_quorum", "default"},
                   {#ctx.notfound_ok, "notfound_ok", "default"},
                   {#ctx.asis, "asis", "false"}]).
  
  %% @spec malformed_rw_param({Idx::integer(), Name::string(), Default::string()},
  %%                          {boolean(), reqdata(), context()}) ->
  