virtual Zlint_code init(Zlint *z) = 0;
virtual Zlint_code recv_gdu(Zlint *z, Z_GDU *gdu) = 0;
virtual Zlint_code recv_fail(Zlint *z, int reason) = 0;
virtual Zlint_code init(Zlint *z) = 0;
virtual Zlint_code recv_gdu(Zlint *z, Z_GDU *gdu) = 0;
virtual Zlint_code recv_fail(Zlint *z, int reason) = 0;