anchor.diff:              end
       end.
   
  +%% @doc Returns a ReadFilter which tests the existens of a value
  +%% in a stored JSON object.
  +-spec get_rf_test_fun(path(), client_value()) -> prbr:read_filter().
  +get_rf_test_fun(Path, Value) ->
  +    fun
  +        (prbr_bottom) -> ?NON_EXIST_VAL;
  +        (Obj)         ->
  +            case dotto:test(Obj, Path, Value) of
  +                {ok, Result} -> Result;
  +                Any -> Any
  +            end
  +    end.
   
   %% %%%%%%%%%%%%%%%%
   %% CONTENT CHECK
  
positive.code:                             end)
              end
      end.
  
negative.code: 
  %% PUBLIC API
  -export([read/1]).
  -export([fetch/2]).
  -export([write/2]).
  
  -export([patch/2]).
  -export([add/3]).
  -export([remove/2]).
  -export([replace/3]).
  -export([move/3]).
  -export([copy/3]).
  -export([test/3]).
  
  %% READ FILTER
  -export([rf_empty/1]).
  