export declare const PS_COOKIE_NAME = "__fs_ps";
export type PersonalizationSegment = 'new' | 'returning';
export declare function setPersonalizationSegment(segment: string | undefined): void;
export declare function getPersonalizationSegment(): PersonalizationSegment | undefined;
export declare function readSegmentFromCookieHeader(header: string | null | undefined): PersonalizationSegment | undefined;