presto-main/src/main/java/io/prestosql/operator/SimplePagesHashStrategy.java/SimplePagesHashStrategy/isSortChannelPositionNull
class SimplePagesHashStrategy:    @Override
    public boolean isSortChannelPositionNull(int blockIndex, int blockPosition)
    {
        return isChannelPositionNull(getSortChannel(), blockIndex, blockPosition);
    }