public markContent(): void {

    const selection = window.getSelection();
    const selectionRange = window.getSelection().getRangeAt(0);

    if (selectionRange.startOffset !== selectionRange.endOffset) {
      if (this.markerEvent === 'p' || this.markerEvent === 'mark' || this.markerEvent === 'strong') {

        const textSeleted = window.getSelection().toString();
        const range = window.getSelection().getRangeAt(0).cloneRange();
        if (this.markerEvent !== 'mark') {
          const marker = document.createElement('mark');
          marker.setAttribute('class', this.colorMarker);
          marker.textContent = textSeleted;

          range.surroundContents(marker);

          this.libraryServices.changeBobblePosition({ top: 0, left: 0, display: 'none' });
        }
      }
    }

  }