export declare const is_plain_object: (val: unknown) => val is Record<string, unknown>;
export declare function merge_nested<T extends Record<string, unknown>>(obj1: T, obj2?: Partial<T>): T;
export declare const escape_html: (unsafe_string: string) => string;
export declare const normalize_unicode_minus: (value: string) => string;
export declare const normalize_scientific_notation: (value: string) => string;
export declare const to_error: (value: unknown) => Error;
export declare function make_change_detector(): (value: unknown) => boolean;
export declare function decode_url_safe_base64(encoded: string): string | undefined;