function determineSlotFunctionResultType(slotFunctionResult) {
  if (slotFunctionResult instanceof Node) {
    return 'node';
  }
  if (isTemplateResult(slotFunctionResult)) {
    return 'template-result';
  }
  if (
    !Array.isArray(slotFunctionResult) &&
    typeof slotFunctionResult === 'object' &&
    'template' in slotFunctionResult
  ) {
    return 'slot-rerender-object';
  }
  return null;
}
@param {SlotFunctionResult} slotFunctionResult
@returns {'template-result'|'node'|'slot-rerender-object'|null}