/**
 * Set parent Toolbar instance.
 *
 * @param   Toolbar  $parent  The parent Toolbar instance to set.
 *
 * @return  static  Return self to support chaining.
 *
 * @since   4.0.0
 */
public function setParent(Toolbar $parent) : self
{
    $this->parent = $parent;
    return $this;
}