code: public Collection<XAttributeNameMap> getAvailableMappings() {
  		HashSet<XAttributeNameMap> result = new HashSet<XAttributeNameMap>();
  		result.addAll(mappings.values());
  		return Collections.unmodifiableCollection(result);
  	}
docs: Returns all available mappings. Note that
  returned mappings may be empty.
  
  @return A collection of all available mappings.