presto-main/src/main/java/io/prestosql/operator/aggregation/histogram/GroupedTypedHistogram.java/GroupedTypedHistogram/writeNodeAsBlock
class GroupedTypedHistogram:        void writeNodeAsBlock(Block valuesBlock, BlockBuilder outputBlockBuilder)
        {
            type.appendTo(valuesBlock, getValuePosition(), outputBlockBuilder);
            BIGINT.writeLong(outputBlockBuilder, getCount());
        }