Additional comment about appliesTo.
Simply subclassing StandardArtifactManager is probably more intuitive than delegating.
Do not set a 10-sec timeout in the build(FreeStyleProject) method.
Generally the environment is responsible for imposing a general timeout on tests.
And this timeout makes debugging more difficult.
Merge branch 'master' into ArtifactManager-JENKINS-17236
Oops, was deleting artifacts from the wrong build.