code: public <T> List<T> getList(RythmConfigurationKey key, Class<T> c) {
          Object o = data.get(key);
          if (null == o) {
              List<T> l = RythmConfigurationKey.getImplList(key.getKey(), raw, c);
              data.put(key, l);
              return l;
          } else {
              return (List) o;
          }
      }
docs: Return a configuration value as list
  
  @param key
  @param c
  @param <T>
  @return the list