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
```
return this._hasFlag(this.flags, flag);
  }
  /**
   * Set the rectangle.
   *
   * @public
   * @memberof Annotation
   * @param {Array} rectangle - The rectangle array with exactly four entries
   */
  setRectangle(rectangle) {
    if (Array.isArray(rectangle) && rectangle.length === 4) {
      this.rectangle = Util.normalizeRect(rectangle);
    } else {
      this.rectangle = [0, 0, 0, 0];
    }
  }
  /**
   * Set the color and take care of color space conversion.
   * The default value is black, in RGB color space.
   *
   * @public
   * @memberof Annotation
   * @param {Array} color - The color array containing either 0
   *                        (transparent), 1 (grayscale), 3 (RGB) or
   *                        4 (CMYK) elements
   */
  setColor(color) {