This is a specific implementation of a Set (heavily based on the HashMap code) that provides for quicker and cached
return of entries in the toArray method.
Hash map holding (key,value) associations of type (int-->Object); Automatically grows and shrinks as needed; Implemented using open addressing with double hashing.
This class is a modified version of the TreeMap class from the
Java Collections Framework.
The changes are to allow SQL type multi-attribute sorting by ordering the entries based on a
modified comparator/search method that allows value ordering as well as key ordering.