/**
  *
  * @param Request $request
  * @return Response
  */
 public function store(Request $request)
 {
     $exercise = new Exercise($request->only('name', 'description', 'step_number', 'default_quantity', 'target', 'priority', 'stretch', 'frequency'));
     $exercise->user()->associate(Auth::user());
     $exercise->program()->associate(ExerciseProgram::find($request->get('program_id')));
     $exercise->series()->associate(Series::find($request->get('series_id')));
     $exercise->defaultUnit()->associate(Unit::find($request->get('default_unit_id')));
     $exercise->save();
     $exercise = $this->transform($this->createItem($exercise, new ExerciseTransformer()))['data'];
     return response($exercise, Response::HTTP_CREATED);
 }