### Question:
BaseUniqueKeyFormatter implements UniqueKeyFormatter { @Override public String formatKeyValue(KeyValue keyValue) { return JOINER.join(encodeAsString(CellUtil.cloneRow(keyValue)), encodeAsString(CellUtil.cloneFamily(keyValue)), encodeAsString(CellUtil.cloneQualifier(keyValue))); }  @Override String formatRow(byte[] row); @Override String formatFamily(byte[] family); @Override String formatKeyValue(KeyValue keyValue); @Override byte[] unformatRow(String keyString); @Override byte[] unformatFamily(String familyString); @Override KeyValue unformatKeyValue(String keyValueString);  }### Answer:
@Test(expected = NullPointerException.class) public void testFormatKeyValue_NullRowKey() { createFormatter().formatKeyValue(new KeyValue()); }