### Question:
BinlogDataId implements DataId { public String dataId() { StringBuilder append = new StringBuilder(COMMON_LEN).append(eventId()).append(SEP).append(ordinal); if (offset != null) { return append.append(SEP).append(offset).toString(); } else { return append.toString(); } } BinlogDataId(String binlogFileName, long tableMapPos, long dataPos); BinlogDataId setOrdinal(int ordinal); BinlogDataId setOffset(Integer offset); String eventId(); String dataId(); @Override boolean equals(Object o); @Override int hashCode(); @Override SyncInitMeta getSyncInitMeta(); @Override int compareTo(DataId dataId); BinlogDataId copyAndSetOrdinal(int ordinal); BinlogDataId copyAndSetOffset(int offset); @Override String toString();  }### Answer:
@Test public void dataId() { }