interface PositionInterface
{
    double getPosition(PageAreaInterface pArea);
}

private double getMinPosition(Collection<PageAreaInterface> pAreas, PositionInterface pPosition)
{
    double lMinPosition = Double.MAX_VALUE;
    for (PageAreaInterface lArea : pAreas)
    {
        lMinPosition = Math.min(lMinPosition, pPosition.getPosition(lArea));
    }
    return lMinPosition;
}

private double getTop(Collection<PageAreaInterface> pAreas)
{
    return getMinPosition(
                pAreas,
                new PositionInterface()
                {
                    @Override
                    public double getPosition(PageAreaInterface pArea)
                    {
                        return pArea.getBoundingBox().getTop();
                    }
                }
    );
}

private double getLeft(Collection<PageAreaInterface> pAreas)
{
    return getMinPosition(
                pAreas,
                new PositionInterface()
                {
                    @Override
                    public double getPosition(PageAreaInterface pArea)
                    {
                        return pArea.getBoundingBox().getLeft();
                    }
                }
    );
}

private double getMaxPosition(Collection<PageAreaInterface> pAreas, PositionInterface pPosition)
{
    double lMaxPosition = Double.MIN_VALUE;
    for (PageAreaInterface lArea : pAreas)
    {
        lMaxPosition = Math.max(lMaxPosition, pPosition.getPosition(lArea));
    }
    return lMaxPosition;
}

private double getBottom(Collection<PageAreaInterface> pAreas)
{
    return getMaxPosition(
                pAreas,
                new PositionInterface()
                {
                    @Override
                    public double getPosition(PageAreaInterface pArea)
                    {
                        return pArea.getBoundingBox().getBottom();
                    }
                }
    );
}

private double getRight(Collection<PageAreaInterface> pAreas)
{
    return getMaxPosition(
                pAreas,
                new PositionInterface()
                {
                    @Override
                    public double getPosition(PageAreaInterface pArea)
                    {
                        return pArea.getBoundingBox().getRight();
                    }
                }
    );
}

min = PageAreaUtils.findMinimum(pageAreas, TOP); // Contrast with...
min = pageAreas.findMinimum(TOP);

min = findMinimum(pageAreas, TOP);    // Minimum pageAreas?! No...
min = findMinimumTop(pageAreas);      // Doesn't read right.
min = findMinimumTopIn(pageAreas);    // Better?
min = findMinimum(TOP).in(pageAreas); // Better?

// In bounding box, collection, or standalone.
public enum POSITION { TOP, LEFT, BOTTOM, RIGHT }

// In bounding box or collection.
public double getPosition(POSITION pos) {
    switch (pos) {
    case TOP:    return getTop();
    case LEFT:   return getLeft();
    case BOTTOM: return getBottom();
    case RIGHT:  return getRight();
    }
    throw new RuntimeException("Bad position provided: " + pos);
}

Collection<PageArea> pageAreas;

public double getMinimumPosition(MyRect.POSITION pos) {
    double min = Double.MAX_VALUE;
    for (PageArea area : pageAreas) {
        min = Math.min(min, area.getBoundingBox().getPosition(pos));
    }
    return min;
}

public double getMaximumPosition(MyRect.POSITION pos) {
    double max = Double.MIN_VALUE;
    for (PageArea area : pageAreas) {
        max = Math.min(max, area.getBoundingBox().getPosition(pos));
    }
    return max;
}

area.getBoundingBox(pos) // or area.getBoundingBoxPosition(pos)?

public abstract class PareAreaComparator implements Comparator<PageAreaInterface> {

    public PareAreaComparator() {
    }

    @Override
    public int compare(final PageAreaInterface o1, final PageAreaInterface o2) {
        final BouningBox boundingBox1 = o1.getBoundingBox();
        final BouningBox boundingBox2 = o2.getBoundingBox();
        return compare(boundingBox1, boundingBox2);
    }

    protected abstract int compare(BouningBox boundingBox1, BouningBox boundingBox2);
}