presto-main/src/main/java/io/prestosql/operator/PagesIndex.java/PagesIndex/positionEqualsPosition
class PagesIndex:    public boolean positionEqualsPosition(PagesHashStrategy partitionHashStrategy, int leftPosition, int rightPosition)
    {
        long leftAddress = valueAddresses.getLong(leftPosition);
        int leftPageIndex = decodeSliceIndex(leftAddress);
        int leftPagePosition = decodePosition(leftAddress);

        long rightAddress = valueAddresses.getLong(rightPosition);
        int rightPageIndex = decodeSliceIndex(rightAddress);
        int rightPagePosition = decodePosition(rightAddress);

        return partitionHashStrategy.positionEqualsPosition(leftPageIndex, leftPagePosition, rightPageIndex, rightPagePosition);
    }