_growRight(width, height) {
    this.root = {
      used: true,
      x: 0,
      y: 0,
      width: this.root.width + width,
      height: this.root.height,
      down: this.root,
      right: {
        x: this.root.width,
        y: 0,
        width,
        height: this.root.height
      }
    };
    const node = this._findNode(this.root, width, height);

    return node ? this._splitNode(node, width, height) : false;
  }
Grow the sprite to the right

@param {number} width        Width
@param {number} height       Height
@returns {object|false}      Node