docs: @Override
      public String toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace) {
          StringBuilder buf = new StringBuilder();
          buf.append('<').append(getElementName()).append(" xmlns=\"").append(getNamespace()).append(
              "\">");
          // Loop through all roster entries and append them to the string buffer
          for (Iterator<RemoteRosterEntry> i = getRosterEntries(); i.hasNext();) {
              RemoteRosterEntry remoteRosterEntry = i.next();
              buf.append(remoteRosterEntry.toXML());
          }
          buf.append("</").append(getElementName()).append('>');
          return buf.toString();
      }