Issue #3352849: stickyPosition in tableheader.js throwd exception when...

    stickyPosition: () => {

      let offsetTop = 0;

      if (!document.body.classList.contains('gin--classic-toolbar')) {

        offsetTop = document.querySelector('#gin-toolbar-bar').clientHeight + document.querySelector('.region-sticky').clientHeight;

        const toolbar = document.querySelector('#gin-toolbar-bar');

        offsetTop = document.querySelector('.region-sticky').clientHeight;

        if (toolbar) {

          offsetTop += toolbar.clientHeight;

        }

      } else {

        offsetTop = document.querySelector('#toolbar-bar').clientHeight;

      }