count(): {all: number, hidden: number, visible: number} {
    return {
      all: this.elementsLength,
      hidden: this.hidden,
      visible: this.elementsLength - this.hidden
    };
  }
}
Show the amount of elements, and those hidden and visible
@function count
@return {object} all matching elements, the amount of hidden and the amount of visible elements
@memberOf holmes