render method
Implementation
@override
void render(Rect area, Buffer buffer, RenderContext ctx) {
final x = area.x + (left ?? 0);
final y = area.y + (top ?? 0);
final w = width ?? area.width - (left ?? 0);
final h = height ?? area.height - (top ?? 0);
ctx.draw(child, Rect(x, y, w, h));
}