default Object transform(Row row) throws Exception {
    throw new UnsupportedOperationException();
  }
When the user specifies {@link MappableRowByRowAccessStrategy} to access the original data in
{@link UDTFConfigurations}, this method will be called to process the transformation. In a
single UDF query, this method may be called multiple times.

@param row original input data row (aligned by time)
@throws Exception the user can throw errors if necessary
@throws UnsupportedOperationException if the user does not override this method
@see MappableRowByRowAccessStrategy
iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/UDTF.java