### Question:
HeaderPacket implements Packet { @Override public void fromByteBuf(final ByteBuf data) { this.packetBodyLength = DataTypesCodec.readUnsignedInt3LE(data); this.setPacketSequenceNumber(data.readByte()); }  @Override ByteBuf toByteBuf(); @Override void fromByteBuf(final ByteBuf data);  }### Answer:
@Test public void assertFromByteBuf() { HeaderPacket actual = new HeaderPacket(); actual.fromByteBuf(getHeaderPacketByteBuf()); assertThat(actual.getPacketSequenceNumber(), is((byte) 1)); assertThat(actual.getPacketBodyLength(), is(PACKET_LENGTH)); }