30   qDeleteAll( mBackends );
 
   35   auto it = std::find_if( mBackends.begin(), mBackends.end(), [ = ]( 
QgsExternalStorage * storage )
 
   37     return storage->type() == type;
 
   40   return it != mBackends.end() ? *it : 
nullptr;
 
   50   if ( !mBackends.contains( storage ) )
 
   51     mBackends.append( storage );
 
   56   const int index = mBackends.indexOf( storage );
 
   59     delete mBackends.takeAt( index );