docs: function (element, options) {
      this.$element      = $(element)
      this.options       = $.extend({}, Collapse.DEFAULTS, options)
      this.$trigger      = $('[data-toggle="collapse"][href="#' + element.id + '"],' +
                             '[data-toggle="collapse"][data-target="#' + element.id + '"]')
      this.transitioning = null
  
      if (this.options.parent) {
        this.$parent = this.getParent()
      } else {
        this.addAriaAndCollapsedClass(this.$element, this.$trigger)
      }
  
      if (this.options.toggle) this.toggle()
    }