A DESCRIPTION OF THE REQUEST :
It would be easy to implement the Comparable interface in SortedSets such as TreeSet by comparing each element in the sets.

JUSTIFICATION :
If TreeSet was comparable, you could create treesets containing treesets.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
@Override
public int compareTo(SortedSet<T> arg0) {
Iterator<T> i = this.iterator();
Iterator<T> j = arg0.iterator();

while(i.hasNext() && j.hasNext())
{
int c = i.next().compareTo(j.next());
if(c!=0){return c;}
}

if(!i.hasNext() && j.hasNext()){return -1;}
if(!j.hasNext() && i.hasNext()){return 1;}

return 0;
}
ACTUAL -
SortedSets are not comparable.