This DEV-only field was added in 836331ba5f69f2cc53b273ec073fae116db14302 by @sebmarkbage but it's not being used anymore to my knowledge.
row = row.sibling;
  }
  return lastContentRow;
}
type SuspenseListRevealOrder = 'forwards' | 'backwards' | 'together' | void;
function validateRevealOrder(revealOrder: SuspenseListRevealOrder) {
  if (__DEV__) {
    if (
      revealOrder !== undefined &&
      revealOrder !== 'forwards' &&
      revealOrder !== 'backwards' &&
      revealOrder !== 'together' &&
      !didWarnAboutRevealOrder[revealOrder]
    ) {
      didWarnAboutRevealOrder[revealOrder] = true;
      if (typeof revealOrder === 'string') {
        switch (revealOrder.toLowerCase()) {
          case 'together':
          case 'forwards':
          case 'backwards': {
            console.error(
              '"%s" is not a valid value for revealOrder on <SuspenseList />. ' +
                'Use lowercase "%s" instead.',
              revealOrder,
              revealOrder.toLowerCase(),
            );
            break;
          }
          case 'forward':
          case 'backward': {