| Interface | Description | 
|---|---|
| ContextCalculator<T extends Contextual> | 
 Calculates the  
Contexts applicable for a Contextual. | 
| ContextSource | 
 A common interface for objects that have a relevant context. 
 | 
| Contextual | 
 A common interface for objects that have an identifier and can have a set of
 active  
Contexts determined. | 
| ContextualService<T extends Contextual> | 
 A common interface for services which provide a means to store and query
 data for  
Contextuals, according to given or calculated
 Context state. | 
| Class | Description | 
|---|---|
| Context | 
 Encapsulates a single attribute about the state or circumstances of a
  
Contextual. |