### Question:
MiruTopologyColumnKeyMarshaller implements TypeMarshaller<MiruTopologyColumnKey> { @Override public MiruTopologyColumnKey fromBytes(byte[] bytes) throws Exception { ByteBuffer buffer = ByteBuffer.wrap(bytes); int partitionId = buffer.getInt(); byte[] hostBytes = new byte[buffer.remaining()]; buffer.get(hostBytes); return new MiruTopologyColumnKey(MiruPartitionId.of(partitionId), hostMarshaller.fromBytes(hostBytes)); }  @Override MiruTopologyColumnKey fromBytes(byte[] bytes); @Override byte[] toBytes(MiruTopologyColumnKey miruTopologyColumnKey); @Override MiruTopologyColumnKey fromLexBytes(byte[] bytes); @Override byte[] toLexBytes(MiruTopologyColumnKey miruTopologyColumnKey);  }### Answer:
@Test public void testFromBytes() throws Exception { MiruTopologyColumnKeyMarshaller marshaller = new MiruTopologyColumnKeyMarshaller(); MiruTopologyColumnKey expected = new MiruTopologyColumnKey(MiruPartitionId.of(123), new MiruHost("logicalName")); MiruTopologyColumnKey actual = marshaller.fromBytes(marshaller.toBytes(expected)); assertEquals(actual.partitionId, expected.partitionId); assertEquals(actual.host, expected.host); }