/**
 * DTO for push notification sender
 * Used to define the details for sending a push notification
 */
export declare class PushSenderDto {
    /**
     * Unique identifier of the message
     * Length restriction from 1 to 255 characters
     */
    messageId: string;
    /**
     * The user ID that will receive the push notification
     * Length restriction from 1 to 255 characters
     */
    userId: string;
    /**
     * The title of the push notification
     * Length restriction from 1 to 255 characters
     */
    title: string;
    /**
     * The content of the push notification
     * Length restriction from 1 to 1000 characters
     */
    message: string;
    /**
     * The subtitle of the push notification (optional)
     * Length restriction from 1 to 255 characters
     */
    subtitle?: string;
}