getSaveCount method Null safety
Returns the number of items on the save stack, including the initial state. This means it returns 1 for a clean canvas, and that each call to save and saveLayer increments it, and that each matching call to restore decrements it.
This number cannot go below 1.
@FfiNative<Int32 Function(Pointer<Void>)>('Canvas::getSaveCount', isLeaf: true) external int getSaveCount();