http://nexus.sonatype.org/oss-repository-hosting.html/vertx-parent/vertx-codegen: Sonatype helps open source projects to set up Maven repositories on https://oss.sonatype.org/ (Eclipse) 
package io.vertx.codegen.annotations;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;


Declares that the value returned by a method will always be the same. Code generators can use this
to cache the proxy of the returned object and avoid to recreate a different proxy for the same object.

/**
 * Declares that the value returned by a method will always be the same. Code generators can use this
 * to cache the proxy of the returned object and avoid to recreate a different proxy for the same object.
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface CacheReturn {
}