anchor.diff:  		{{_, Op}, {_, Path}, {_, Value}} ->
   			{Op, Path, Value};
   		_ ->
  -			{error, 400}
  +			{error, malformed_request}
   	end.
   
   -spec patch_replace(Path , Value, Subscriber) -> ok
  
positive.code: 		true ->
  			validate_operation2(OpT, PathT, ValueT);
  		false ->
  			{error, 400}
  	end.
  %% @hidden
  validate_operation2(OpT, PathT, ValueT) ->
  
negative.code: 		{_, "add"} ->
  			validate_operation1(add, OpT, PathT, ValueT);
  		_ ->
  			{error, malformed_request}
  	end.
  %% @hidden
  validate_operation1(replace, OpT, {_, Path} = PathT, ValueT) ->
  