public void setDataType(TSDataType dataType, int i) {
    if (dataTypes == null) {
      dataTypes = new TSDataType[measurements.length];
    }
    this.dataTypes[i] = dataType;
  }
it is the end of current range.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/crud/InsertBaseStatement.java