/**
  * Update the specified resource in storage.
  *
  * @param  int  $id
  * @return Response
  */
 public function update(DataValue $dataValue, Request $request)
 {
     $input = array_except($request->all(), ['_method', '_token', 'time-label']);
     $dataValue->update($input);
     Cache::flush();
     return redirect()->route('variables.show', $dataValue->fk_var_id)->with('message', 'Value updated.');
 }