code: public static String getFirstFullTangoHost() throws DevFailed {
          // TODO
          final String TANGO_HOST_ERROR = "API_GetTangoHostFailed";
  
          // Get the tango_host
          String host = getFirstHost();
  
          try {
              // Get FQDN for host
              final InetAddress iadd = InetAddress.getByName(host);
              host = iadd.getCanonicalHostName();
          } catch (final UnknownHostException e) {
              throw DevFailedUtils.newDevFailed(TANGO_HOST_ERROR, e.toString());
          }
  
          return host + ':' + getFirstPort();
      }
docs: Returns the TANGO_HOST with full qualified name.
  
  @param tangoHost default Tango_host
  @return the TANGO_HOST with full qualified name.
  @throws DevFailed if TANGO_HOST value has a bad syntax.