const fence: <T>(
  calls?: 
  | string
  | number
  | false
  | DeferredCall<any>
  | ArrowFunction
  | LiveElement<ArrowFunction>[]
  | ReactElementInterop
  | LiveNode<any>[],
  then?: (r: T) => LiveElement,
  fallback?: NonNullable<T>,
  key?: Key,
) => DeferredCall<() => void>
Fence gathered items from a subtree.
packages / live / src / builtin.ts