code: function() {
          if (this._opening || this.dropdown || !this.triggerEvent('selectivity-opening')) {
              return;
          }
  
          this._opening = true;
  
          var Dropdown = this.options.dropdown || Selectivity.Dropdown;
          if (Dropdown) {
              this.dropdown = new Dropdown(this, {
                  items: this.items,
                  position: this.options.positionDropdown,
                  query: this.options.query,
                  showSearchInput: this.options.showSearchInputInDropdown !== false
              });
          }
  
          this.search('');
  
          this.focus();
  
          toggleClass(this.el, 'open', true);
  
          this._opening = false;
      }
docs: Opens the dropdown.