export declare function pickString(record: Record<string, unknown>, keys: string[]): string | null;
export declare function pickNumber(record: Record<string, unknown>, keys: string[]): number | null;
export declare function pickBoolean(record: Record<string, unknown> | null, keys: string[]): boolean | null;
export declare function pickHeaderString(headers: Record<string, string | string[] | undefined>, keys: string[]): string | null;
export declare function toIsoString(value: string | null): string | null;
export declare function parsePositiveInt(raw: string | null, fallback: number, max?: number): number;
export declare function parseBooleanQuery(raw: string | null): boolean;