code: private static List<Object> getTypeKeys(Conversion<?> conversion) {
  
  		List<Object> result=new ArrayList<Object>();
  
  		synchronized (typeConversions) {
  			// Clone the conversions
  			Map<Object,Conversion<?>> map=
  				new HashMap<Object,Conversion<?>>(typeConversions);
  
  			// Find all keys that map to this conversion instance
  			for (Map.Entry<Object,Conversion<?>> entry: map.entrySet()) {
  				if (entry.getValue() == conversion) {
  					result.add(entry.getKey());
  				}
  			}
  		}
  
  		return result;
  	}
docs: Discover all the type key mappings for this conversion