code: function MultipleInput(options) {
      Selectivity.call(
          this,
          assign(
              {
                  // dropdowns for multiple-value inputs should open below the select box,
                  // unless there is not enough space below, but there is space enough above, then it should
                  // open upwards
                  positionDropdown: function(el, selectEl) {
                      var rect = selectEl.getBoundingClientRect();
                      var dropdownHeight = el.clientHeight;
                      var openUpwards =
                          rect.bottom + dropdownHeight > window.innerHeight &&
                          rect.top - dropdownHeight > 0;
  
                      assign(el.style, {
                          left: rect.left + 'px',
                          top: (openUpwards ? rect.top - dropdownHeight : rect.bottom) + 'px',
                          width: rect.width + 'px'
                      });
                  },
  
                  showSearchInputInDropdown: false
              },
              options
          )
      );
  
      this._reset();
  
      var events = {
          change: this.rerenderSelection,
          click: this._clicked,
          'selectivity-selected': this._resultSelected
      };
      events['change ' + INPUT_SELECTOR] = stopPropagation;
      events['click ' + SELECTED_ITEM_SELECTOR] = this._itemClicked;
      events['click ' + SELECTED_ITEM_SELECTOR + '-remove'] = this._itemRemoveClicked;
      events['keydown ' + INPUT_SELECTOR] = this._keyHeld;
      events['keyup ' + INPUT_SELECTOR] = this._keyReleased;
      events['paste ' + INPUT_SELECTOR] = this._onPaste;
  
      this.events.on(events);
  }
docs: MultipleInput Constructor.