/**
 * Resolves the request id to use for correlating log lines, preferring a client-supplied
 * `x-request-id` header. Rejects values that are empty, too long, or contain control
 * characters (e.g. newlines), falling back to a generated id instead - the header is
 * attacker-controlled and gets embedded verbatim into every log line for the request.
 */
export declare function getRequestId(headerValue: string | null | undefined, generateId: () => string): string;