code: @Override
      public boolean loadValuesFrom(String filename) {
          String yamlStr = textIn(filename);
          Object y = yaml.load(yamlStr);
          if (y instanceof Map) {
              getCurrentValues().putAll((Map) y);
          } else {
              getCurrentValues().put("elements", y);
          }
          return true;
      }
docs: Adds the yaml loaded from the specified file to current values.
  @param filename YAML file to load
  @return true when file is loaded