code: private void setFromEnv() throws DevFailed {
          String env = TangoEnv.getTangoHost();
          assert env != null;
          if (!env.contains(":"))
              Except.throw_connection_failed("TangoApi_TANGO_HOST_NOT_SET",
                      "Unknown \"TANGO_HOST\" property " + env,
                      "TangoUrl.setFromEnv()");
          String[] array = ApiUtil.parseTangoHost(env);
          host = array[0];
          strPort = array[1];
          port = Integer.parseInt(strPort);
          envRead = true;
          fromEnv = true;
      }
docs: ===================================================================