presto-main/src/main/java/io/prestosql/operator/index/DynamicTupleFilterFactory.java/DynamicTupleFilterFactory/getFilterTuple
class DynamicTupleFilterFactory:    private Page getFilterTuple(Page tuplePage)
    {
        Block[] normalizedBlocks = new Block[tupleFilterChannels.length];
        for (int i = 0; i < tupleFilterChannels.length; i++) {
            normalizedBlocks[i] = tuplePage.getBlock(tupleFilterChannels[i]);
        }
        return new Page(normalizedBlocks);
    }