docs: public static void preApproveSubscriptionIfRequiredAndPossible(Roster roster, BareJid jid)
              throws NotLoggedInException, NotConnectedException, InterruptedException {
          if (!roster.isSubscriptionPreApprovalSupported()) {
              return;
          }
  
          RosterEntry entry = roster.getEntry(jid);
          if (entry == null || (!entry.canSeeMyPresence() && !entry.isApproved())) {
              try {
                  roster.preApprove(jid);
              } catch (FeatureNotSupportedException e) {
                  // Should never happen since we checked for the feature above.
                  throw new AssertionError(e);
              }
          }
      }