index property
      
      int
      get
      index
      
    
    
The position to move the group to. Use -1 to place the group at the end
of the window.
Implementation
int get index => _wrapped.index;
      
      set
      index
      (int v) 
      
    
    
    
Implementation
set index(int v) {
  _wrapped.index = v;
}