MemberLevelComparator is used to compare two com.sas.storage.olap.MemberInterface objects by the depth of the
level the members belong to. This is useful to sort an array of MemberInterface objects, such as that returned from
the getMembers method of the com.sas.storage.olap.MetadataInterface, as this method is not guaranteed
to return the members in any order.
Compares two com.sas.storage.olap.MemberInterface objects by their level depth value.
Returns a negative integer, indicating member1 is less than member2, if member1 is null
or if the depth of the level member1 belongs to is less than that of member2's level depth.
Returns 0 if member1 is equal to member2, or if their level depths are the same.
Returns a positive integer, indicating member1 is greater than member2, if member2
is null or if member2's level depth less than that of member1's level depth.