export function findDuplicate(keys: string[]) {
  const elementCount = new Map<string, number>();
  for (const key of keys) {
    if (key === '') continue;
    elementCount.set(key, (elementCount.get(key) || 0) + 1);
  }

  return Array.from(elementCount)
    .filter(([_, count]) => count > 1)
    .map(([item, _]) => item);
}