import java.io.Serializable;
import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.yangtools.concepts.Immutable;
public abstract class Envelope<T extends Message<?, ?>> implements Immutable, Serializable {
import java.io.Serializable;
import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.yangtools.concepts.Immutable;
public abstract class Envelope<T extends Message<?, ?>> implements Immutable, Serializable {