) {
          deleteRemainingChildren(returnFiber, child.sibling);
          const existing = useFiber(
            child,
            portal.children || [],
            expirationTime,
          );
          existing.return = returnFiber;
          return existing;
        } else {
          deleteRemainingChildren(returnFiber, child);
          break;
        }
      } else {
        deleteChild(returnFiber, child);
      }
      child = child.sibling;
    }
    const created = createFiberFromPortal(
      portal,
      returnFiber.mode,
      expirationTime,
    );
    created.return = returnFiber;
    return created;
  }
  // 
  // 
  // 
  function reconcileChildFibers(