let toString = function() {
    let str = '';
// retunerar
    for (let y = 0; y < this.y; y += 1) {
      for (let x = 0; x < this.x; x += 1) {
        str += '®';
        if (x < this.x - 1) {
          str += ' ';
        }
      }

      if (y < this.y - 1) {
        str += '\n';
      }
    }

    return str;
  };

  // Create an object and return it.
  return {
    x: x,
    y: y,
    color: color,
    toString,
    render
  };
};