docs: private Chat getUserChat(Jid userJID) {
          if (matchMode == MatchMode.NONE) {
              return null;
          }
          // According to RFC6120 8.1.2.1 4. messages without a 'from' attribute are valid, but they
          // are of no use in this case for ChatManager
          if (userJID == null) {
              return null;
          }
          Chat match = jidChats.get(userJID);
  
          if (match == null && (matchMode == MatchMode.BARE_JID)) {
              EntityBareJid entityBareJid = userJID.asEntityBareJidIfPossible();
              if (entityBareJid != null) {
                  match = baseJidChats.get(entityBareJid);
              }
          }
          return match;
      }