presto-orc/src/main/java/io/prestosql/orc/DictionaryCompressionOptimizer.java/DictionaryCompressionProjection/DictionaryCompressionProjection
class DictionaryCompressionProjection:        public DictionaryCompressionProjection(DictionaryColumnManager columnToConvert, double predictedFileCompressionRatio)
        {
            this.columnToConvert = requireNonNull(columnToConvert, "columnToConvert is null");
            this.predictedFileCompressionRatio = predictedFileCompressionRatio;
        }