setAttributes = (el, attrs) => {
  pair.forEach(attrs, (key, value) => {
    if (value === false) {
      el.removeAttribute(key);
    } else if (value === true) {
      el.setAttribute(key, '');
    } else {
      // @ts-ignore
      el.setAttribute(key, value);
    }
  });
  return el;
}
@param {Element} el
@param {Array<pair.Pair<string,string|boolean>>} attrs Array of key-value pairs
@return {Element}