anchor.diff:    }) {
       assert(clipBehavior != null); // ignore: unnecessary_null_comparison
       assert(clipBehavior != ui.Clip.none);
  -    return _pushSurface(PersistedClipPath(oldLayer as PersistedClipPath?, path, clipBehavior)) as ui.ClipPathEngineLayer;
  +    return _pushSurface<PersistedClipPath>(PersistedClipPath(oldLayer as PersistedClipPath?, path, clipBehavior));
     }
   
     /// Pushes an opacity operation onto the operation stack.
  
positive.code:   }) {
      assert(clipBehavior != null); // ignore: unnecessary_null_comparison
      assert(clipBehavior != ui.Clip.none);
      return _pushSurface(PersistedClipRect(oldLayer as PersistedClipRect?, rect, clipBehavior))
          as ui.ClipRectEngineLayer;
    }
  
    /// Pushes a rounded-rectangular clip operation onto the operation stack.
  
negative.code:     double dy, {
      ui.OffsetEngineLayer? oldLayer,
    }) {
      return _pushSurface<PersistedOffset>(PersistedOffset(oldLayer as PersistedOffset?, dx, dy));
    }
  
    /// Pushes a transform operation onto the operation stack.
  