/**
 * Removes a user from an email or SMS subscription group.
 *
 * @param subscriptionGroupId - The unique identifier of the subscription group.
 *
 * @returns Resolves to a boolean that indicates whether the update was successfully enqueued. Resolves to undefined
 *   if the SDK is not initialized.
 */
export declare function removeUserFromSubscriptionGroup(subscriptionGroupId: string): Promise<boolean | undefined>;