presto-rcfile/src/main/java/io/prestosql/rcfile/RcFileWriter.java/ColumnEncoder/ColumnEncodeOutput
class ColumnEncoder:            public ColumnEncodeOutput(SliceOutput lengthOutput, SliceOutput valueOutput)
            {
                this.lengthOutput = lengthOutput;
                this.valueOutput = valueOutput;
                this.previousOffset = valueOutput.size();
                this.previousLength = -1;
            }