export declare const getServerSideABVariant: <D extends {
    abVariant?: Record<string, unknown>;
    enableABTesting?: boolean;
    posthogFeatureFlagKey?: string;
}, T extends Record<string, unknown> = Record<string, unknown>>(document: D & T, cookies: {
    get: (name: string) => {
        value: string;
    } | undefined;
}) => Promise<T>;