code: private void addIntoEquivalanceMap(BioPAXElement bpe)
  	{
  		int key = bpe.hashCode();
  		List<BioPAXElement> list = equivalenceMap.get(key);
  		if (list == null)
  		{
  			list = new ArrayList<BioPAXElement>();
  			equivalenceMap.put(key, list);
  		}
  		list.add(bpe);
  	}
docs: Adds a BioPAX element into the equivalence map.
  
  @param bpe BioPAX element to be added into the map.