text: 
  import { LitElement, html } from 'lit-element';
  
  export class BsCollapseMultiToggle extends LitElement {
      
      static get properties() {
          return {
              multiTarget: {type: String, reflect: true}
          };
      }
      
      render() {
          return html`
              <slot></slot>
          `;
      }
      
      constructor() {
          super();
          this.multiTarget = '';
      }
      
      firstUpdated() {
          this.addEventListener('bs-button-click', event => this._handleMultiToggleCollapse(event));
      }
      
      _handleMultiToggleCollapse() {
          
          if(!this.multiTarget) {
              return;
          }
  
          const multiToggleCollapseEvent = new CustomEvent('bs-collapse-multi-toggle', {
              bubbles: true, 
              composed: true,
              detail: {
                  multiTarget: this.multiTarget
              }
          });
          
          this.dispatchEvent(multiToggleCollapseEvent);
      }
  };
  
  window.customElements.define('bs-collapse-multi-toggle', BsCollapseMultiToggle);