| Class Summary | 
| AddressValidatorImpl | This class provides a default implementation of AddressValidator. | 
| ConcurrentUpdateDetector | This class is intended to detect concurrent update attemps by checking
 exceptions to see if they are, or contain, ConcurrentUpdateExceptions (CUE) or
 InvalidVersionExceptions (IVE). | 
| ContextValueRetriever | Determines the appropriate value for a profile property based on a site,
 and possibly what is already in the profile. | 
| MapToArrayDefaultFirst | This droplet is used to convert a map of items to a sorted array of map entries
 with the default item in the beginning of the array. | 
| PlaceList | This class represents a list of places, each of which has a code and an
 associated display name. | 
| PlaceList.Place | Inner class used to associate a code with a display name to
 define a single place. | 
| RepeatingRequestMonitor | The class
 RepeatingRequestMonitoris designed for use as a session scoped
 component. | 
| TransactionLockFactory | The transaction lock factory is used to grab locks before beginning and ending
 a transaction. | 
| TransactionLockService | This class is used to acquire and release locks that are used before and after creating new transactions. |