code: function findDelegate(start) {
    let frag = start;
    let delegate, el;
  
    out: while (frag) {
      // find next element
      el = 0;
      while (!el && frag) {
        if (frag.owner.type === ELEMENT) el = frag.owner;
        if (frag.owner.ractive && frag.owner.ractive.delegate === false) break out;
        frag = frag.parent || frag.componentParent;
      }
  
      if (el.delegate === false) break out;
      delegate = el.delegate || el;
  
      // find next repeated fragment
      while (frag) {
        if (frag.iterations) break;
        if (frag.owner.ractive && frag.owner.ractive.delegate === false) break out;
        frag = frag.parent || frag.componentParent;
      }
    }
  
    return delegate;
  }
docs: find the topmost delegate