Function normalizeForBTree

packages/db/src/utils/comparison.ts:222–227

(value: any)

 * (it interprets undefined as "start from beginning" in nextHigherPair/nextLowerPair).
 */
export function normalizeForBTree(value: any): any {
  if (value === undefined) {
    return UNDEFINED_SENTINEL
  }
  return normalizeValue(value)
}

/**
 * Converts the `UNDEFINED_SENTINEL` back to `undefined`.