export declare enum AckType {
    MD_DOWNGRADE = -7,
    INACTIVE = -6,
    CONTENT_UNUPLOADABLE = -5,
    CONTENT_TOO_BIG = -4,
    CONTENT_GONE = -3,
    EXPIRED = -2,
    FAILED = -1,
    CLOCK = 0,
    SENT = 1,
    RECEIVED = 2,
    READ = 3,
    PLAYED = 4
}