presto-orc/src/main/java/io/prestosql/orc/reader/SliceDictionaryColumnReader.java/SliceDictionaryColumnReader/SliceDictionaryColumnReader
class SliceDictionaryColumnReader:    public SliceDictionaryColumnReader(OrcColumn column, LocalMemoryContext systemMemoryContext, int maxCodePointCount, boolean isCharType)
    {
        this.maxCodePointCount = maxCodePointCount;
        this.isCharType = isCharType;
        this.column = requireNonNull(column, "column is null");
        this.systemMemoryContext = requireNonNull(systemMemoryContext, "systemMemoryContext is null");
    }