weld/subsystem/src/main/java/org/jboss/as/weld/_private/WeldDeploymentMarker.java
public static void mark(DeploymentUnit unit) {
        unit.putAttachment(MARKER, Boolean.TRUE);
        if (unit.getParent() != null) {
            mark(unit.getParent());
        }
    }
public static void mark(DeploymentUnit unit) {
        unit.putAttachment(MARKER, Boolean.TRUE);
        if (unit.getParent() != null) {
            mark(unit.getParent());
        }
    }
Mark this deployment and the top level deployment as being a weld deployment.