import java.io.DataInput;
import java.io.DataOutput;
import java.io.Externalizable;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.Externalizable;
private final long generation;
ClientIdentifier(final FrontendIdentifier frontendId, final long generation) {
private final long generation;
ClientIdentifier(final FrontendIdentifier frontendId, final long generation) {