docs: public RemoteProxy remove(RemoteProxy proxy) {
      // Find the original proxy. While the supplied one is logically equivalent, it may be a fresh object with
      // an empty TestSlot list, which doesn't figure into the proxy equivalence check.  Since we want to free up
      // those test sessions, we need to operate on that original object.
      for (RemoteProxy p : proxies) {
        if (p.equals(proxy)) {
          proxies.remove(p);
          return p;
        }
      }
      throw new IllegalStateException("Did not contain proxy" + proxy);
    }