enable() {
    if (!this.textDivs || !this.textContentItemsStr) {
      throw new Error("Text divs and strings have not been set.");
    }
    if (this.enabled) {
      throw new Error("TextHighlighter is already enabled.");
    }
    this.enabled = true;

    if (!this.#eventAbortController) {
      this.#eventAbortController = new AbortController();

      this.eventBus._on(
        "updatetextlayermatches",
        evt => {
          if (evt.pageIndex === this.pageIdx || evt.pageIndex === -1) {
            this._updateMatches();
          }
        },
        { signal: this.#eventAbortController.signal }
      );
    }
    this._updateMatches();
  }
Start listening for events to update the highlighter and check if there are
any current matches that need be highlighted.