anchor.diff:  
   Also when used from XML, Ehcache expects your expiry implementation to have a _no-arg_ constructor.
   
  -Once you have implemented your own expiry, simply configure it.
  +Once you have implemented your own expiry policy, simply configure it.
   
   In Java:
   
  
positive.code: == Introduction
  
  As conveyed in the <<caching-concepts.adoc#data-freshness-and-expiration,_Data Freshness and Expiration_>> documentation, this is one of the key aspects of caching.
  In Ehcache 3 this is addressed with the `Expiry` interface and its use in controlling the age of cache mappings.
  
  == Configuration
  
  
negative.code: time-to-live:: this means cache mappings will expire after a fixed duration following their creation,
  time-to-idle:: this means cache mappings will expire after a fixed duration following the time they were last accessed.
  
  For Java, see `org.ehcache.config.builders.ExpiryPolicyBuilder` and the XSD for XML.
  
  Read on to implement your own expiration scheme.
  
  == Custom expiry
  
  Supporting your own expiration scheme simply means implementing the `ExpiryPolicy` interface:
  
  [source,java,indent=0]
  ----
  include::{sourcedir35}/api/src/main/java/org/ehcache/expiry/ExpiryPolicy.java[lines=21..-1]
  ----
  
  The main points to remember on the return value from these methods:
  