The scale of this node relative its parent.
The scale property is only valid if scaleX and scaleY are equal values.
myNode.scale = 5.0;
Source
double get scale { assert(_scaleX == _scaleY); return _scaleX; }
Source
set scale(double scale) { assert(scale != null); _scaleX = _scaleY = scale; invalidateTransformMatrix(); }