RetentionPolicy (Parent module for everything of interest. 6.2.3 API)

All Known Implementing Classes:

MaxAgePolicy, MaxCacheSizePolicy, ValidTimestampPolicy
```
public interface RetentionPolicy<K,V>
```
Created by Jeff Gaynor
on Nov 11, 2010 at 1:03:54 PM

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`applies()`	If this applies to the current cache.
`Map<K,V>`	`getMap()`	The cache to which this policy is applied.
`boolean`	`retain(K key, V value)`

- Method Detail
  - retain
```
boolean retain(K key,
               V value)
```
  - getMap
```
Map<K,V> getMap()
```
    The cache to which this policy is applied.
    
    Returns:
  - applies
```
boolean applies()
```
    If this applies to the current cache. While this is true, the retain(Object, Object) method will be applied to each element of the cache. When false, this policy will be skipped.
    E.g. for a cache that limits the number of cached items, there is no reason to check every item in the cache directly if the cache size is below a certain threshold.
    
    Returns: