_makeAncestorsOverflowVisible() {
      this.ancestorsChanged = $();
      let ancestor = this.placeholder[0].parentNode;
      while (ancestor !== null && !$(ancestor).is(document)) {
        let curr = $(ancestor);
        if (curr.css('overflow') !== 'visible') {
          curr.css('overflow', 'visible');
          if (this.ancestorsChanged === undefined) {
            this.ancestorsChanged = curr;
          } else {
            this.ancestorsChanged = this.ancestorsChanged.add(curr);
          }
        }
        ancestor = ancestor.parentNode;
      }
    }
Find ancestors with overflow: hidden; and make visible