presto-hive/src/main/java/io/prestosql/plugin/hive/HiveCoercionRecordCursor.java/HiveCoercionRecordCursor/advanceNextPosition
class HiveCoercionRecordCursor:    @Override
    public boolean advanceNextPosition()
    {
        for (int i = 0; i < columnMappings.size(); i++) {
            if (coercers[i] != null) {
                coercers[i].reset();
            }
        }
        return delegate.advanceNextPosition();
    }