public Class<?> getClass(final String key, final boolean initialize, final ClassLoader cl) {
    try {
      if (containsKey(key)) {
        return Class.forName(get(key), initialize, cl);
      } else {
        throw new UndefinedPropertyException("Missing required property '"
            + key + "'");
      }
    } catch (final ClassNotFoundException e) {
      throw new IllegalArgumentException(e);
    }
  }
Attempts to return the Class that corresponds to the Props value. If the class doesn't exit, an
IllegalArgumentException will be thrown.
dss-appconn/appconns/dss-eventchecker-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/eventchecker/utils/Props.java