Hi!

Had issue with round rectangles in my custom shape not being rendered after calling roundrect.

After looking up sources, I noticed that at the beginning of roundrect function there is check if (!this.node) return; before calling rect().

  roundrect(x: number, y: number, w: number, h: number, dx: number, dy: number) {
    if (!this.node) return;

    this.rect(x, y, w, h);

    ...

So I'm wondering why it's here. Calling begin before roundrect seems to fix issue, because begin() initialize node variable, but rect() will initialize it anyway.