code: public URI getUri(final String name) {
      if (containsKey(name)) {
        try {
          return new URI(get(name));
        } catch (final URISyntaxException e) {
          throw new IllegalArgumentException(e.getMessage());
        }
      } else {
        throw new UndefinedPropertyException("Missing required property '" + name
            + "'");
      }
    }
docs: Returns the uri representation of the value. If the value is null, then the default value is
  returned. If the value isn't a uri, then a IllegalArgumentException will be thrown.