import { EnsureBaseOptions, EnsureIsOptional, EnsureDefault } from '../ensure'; declare function ensureError(value: any, options?: EnsureBaseOptions): Error; declare function ensureError(value: any, options?: EnsureBaseOptions & EnsureIsOptional): Error | null; declare function ensureError(value: any, options?: EnsureBaseOptions & EnsureIsOptional & EnsureDefault): Error; export default ensureError;