private XmppAxolotlSession recreateUncachedSession(AxolotlAddress address) {
   IdentityKey identityKey =
       axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
   return (identityKey != null)
       ? new XmppAxolotlSession(
           account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""))
       : null;
 }
  public Set<AxolotlAddress> findDevicesWithoutSession(final Conversation conversation) {
    Log.d(
        Config.LOGTAG,
        AxolotlService.getLogprefix(account)
            + "Finding devices without session for "
            + conversation.getContact().getJid().toBareJid());
    Jid contactJid = conversation.getContact().getJid().toBareJid();
    Set<AxolotlAddress> addresses = new HashSet<>();
    if (deviceIds.get(contactJid) != null) {
      for (Integer foreignId : this.deviceIds.get(contactJid)) {
        AxolotlAddress address = new AxolotlAddress(contactJid.toString(), foreignId);
        if (sessions.get(address) == null) {
          IdentityKey identityKey =
              axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
          if (identityKey != null) {
            Log.d(
                Config.LOGTAG,
                AxolotlService.getLogprefix(account)
                    + "Already have session for "
                    + address.toString()
                    + ", adding to cache...");
            XmppAxolotlSession session =
                new XmppAxolotlSession(
                    account,
                    axolotlStore,
                    address,
                    identityKey.getFingerprint().replaceAll("\\s", ""));
            sessions.put(address, session);
          } else {
            Log.d(
                Config.LOGTAG,
                AxolotlService.getLogprefix(account)
                    + "Found device "
                    + account.getJid().toBareJid()
                    + ":"
                    + foreignId);
            addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
          }
        }
      }
    } else {
      Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
    }
    if (deviceIds.get(account.getJid().toBareJid()) != null) {
      for (Integer ownId : this.deviceIds.get(account.getJid().toBareJid())) {
        AxolotlAddress address = new AxolotlAddress(account.getJid().toBareJid().toString(), ownId);
        if (sessions.get(address) == null) {
          IdentityKey identityKey =
              axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
          if (identityKey != null) {
            Log.d(
                Config.LOGTAG,
                AxolotlService.getLogprefix(account)
                    + "Already have session for "
                    + address.toString()
                    + ", adding to cache...");
            XmppAxolotlSession session =
                new XmppAxolotlSession(
                    account,
                    axolotlStore,
                    address,
                    identityKey.getFingerprint().replaceAll("\\s", ""));
            sessions.put(address, session);
          } else {
            Log.d(
                Config.LOGTAG,
                AxolotlService.getLogprefix(account)
                    + "Found device "
                    + account.getJid().toBareJid()
                    + ":"
                    + ownId);
            addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
          }
        }
      }
    }

    return addresses;
  }
 public void purgeKey(IdentityKey identityKey) {
   axolotlStore.setFingerprintTrust(
       identityKey.getFingerprint().replaceAll("\\s", ""), XmppAxolotlSession.Trust.COMPROMISED);
 }