src/main/java/com/googlecode/objectify/ObjectifyFactory.java
public AsyncDatastore asyncDatastore(final boolean enableGlobalCache) {
		if (this.entityMemcache != null && enableGlobalCache && this.registrar.isCacheEnabled())
			return new CachingAsyncDatastore(asyncDatastore(), this.entityMemcache);
		else
			return asyncDatastore();
	}
public AsyncDatastore asyncDatastore(final boolean enableGlobalCache) {
		if (this.entityMemcache != null && enableGlobalCache && this.registrar.isCacheEnabled())
			return new CachingAsyncDatastore(asyncDatastore(), this.entityMemcache);
		else
			return asyncDatastore();
	}
Might produce a caching version if caching is enabled.