running error-prone on jdk/jdk found the following deffect in java.rmi module:
  
src/java.rmi/share/classes/sun/rmi/server/ActivationGroupImpl.java:447: warning: [HashtableContains] contains() is a legacy method that is equivalent to containsValue(), but the argument type 'java.rmi.activation.ActivationID' looks like a key
            if (!active.contains(id)) {
                                ^
    (see https://errorprone.info/bugpattern/HashtableContains.md)
  Did you mean 'if (!active.containsKey(id)) {'?