presto-kinesis/src/main/java/io/prestosql/plugin/kinesis/KinesisRecordSet.java/KinesisRecordSet/isNull
class KinesisRecordSet:        @Override
        public boolean isNull(int field)
        {
            checkArgument(field < columnHandles.size(), "Invalid field index");
            return currentRowValues[field] == null || currentRowValues[field].isNull();
        }