public function storeLayer($request)
 {
     $layer = new Layer();
     $values = $request->except('_token', '_method', 'map_id', 'source_id');
     $layer->fill($values);
     $map = Map::findOrFail($request->map_id);
     $layer->map()->associate($map);
     $source = Source::findOrFail($request->source_id);
     $layer->source()->associate($source);
     $layer->save();
     return $layer;
 }
 public function destroyMap($id)
 {
     $map = Map::findOrFail($id);
     $result = Map::destroy($id);
     return $result;
 }