public boolean isClosed() {
    return isClosed.get();
  }
Release all memory of this block.

<p>NOTE: This method should be called only by {@link LoadTsFileAbstractMemoryBlock#close()}.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/load/memory/LoadTsFileAbstractMemoryBlock.java