scanForwardQuery = function(start, match, global) {
    const results = asParentNode(getRootNode(start, global)).querySelectorAll(match)
    for (let i = 0; i < results.length; i++) {
      const elt = results[i]
      if (elt.compareDocumentPosition(start) === Node.DOCUMENT_POSITION_PRECEDING) {
        return elt
      }
    }
  }
@param {Node} start
@param {string} match
@param {boolean} global
@returns {Element}