Configuration:
- PDF.js version: 2.0.550

Steps to reproduce the problem:
1. Render document in SVG mode `renderMode="svg"`

What is the expected behavior? (add screenshot)
Rendering annotations same way as they rendered on canvas

What went wrong? (add screenshot)
```
Warning: Unimplemented operator beginAnnotations
Warning: Unimplemented operator endAnnotations
```
this.current.strokeColor = this.getColorN_Pattern(arguments);
    }
    setFillColorN() {
      this.current.fillColor = this.getColorN_Pattern(arguments);
      this.current.patternFill = true;
    }
    setStrokeRGBColor(r, g, b) {
      const color = Util.makeHexColor(r, g, b);
      this.ctx.strokeStyle = color;
      this.current.strokeColor = color;
    }
    setFillRGBColor(r, g, b) {
      const color = Util.makeHexColor(r, g, b);
      this.ctx.fillStyle = color;
      this.current.fillColor = color;
      this.current.patternFill = false;
    }
    shadingFill(patternIR) {
      if (!this.contentVisible) {
        return;
      }
      const ctx = this.ctx;
      this.save();
      const pattern = getShadingPattern(patternIR);
      ctx.fillStyle = pattern.getPattern(
        ctx,
        this,
        ctx.mozCurrentTransformInverse,
        true