private long allocateUniqueStamp() {
    if (++stampAllocator < 0) {
      stampAllocator = 1;
    }
    return stampAllocator;
  }
Allocate unique stamp based on stampAllocator. Because stamp is non-negative, overflow needs to
be avoided.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/lock/StampedWriterPreferredLock.java