code: @Override
      public <T> T getOrDie(String key, Class<T> clazz) {
          T val = get(key, clazz);
          if (val == null) {
              throw new IllegalArgumentException(String.format(ERROR_KEYNOTFOUND, key));
          }
          return val;
      }
docs: Get a custom type property. The object is created using the
  {@link org.wisdom.api.content.ParameterFactories} strategy. This "die" method forces this key to be set.
  Otherwise a runtime exception will be thrown.
  
  @param key   the key the key used in the configuration file.
  @param clazz the class of the object to create
  @return the created object. The object cannot be created (because the property is missing,
  or because the conversion failed) a {@link RuntimeException} is thrown.