protected static AlignedWritableMemChunkGroup deserialize(
      DataInputStream stream, boolean isTableModel) throws IOException {
    AlignedWritableMemChunkGroup memChunkGroup = new AlignedWritableMemChunkGroup();
    memChunkGroup.memChunk = AlignedWritableMemChunk.deserialize(stream, isTableModel);
    return memChunkGroup;
  }
Check whether this MemChunkGroup contains a measurement. If a VECTOR_PLACEHOLDER passed from
outer, always return true because AlignedMemChunkGroup existing.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/memtable/AlignedWritableMemChunkGroup.java