function compareValues(base, other) {
  const basePart = isNumber(base) ? base : 'N/A';
  const otherPart = isNumber(other) ? other : 'N/A';
  return {
    description: `${basePart} -> ${otherPart}`,
    delta: isNumber(base) && isNumber(other) ? (other - base) : undefined,
  };
}
@param {number=} base
@param {number=} other