code: public <T> T get(RythmConfigurationKey key) {
          Object o = data.get(key);
          if (null == o) {
              o = key.getConfiguration(raw);
              if (null != o) {
                  data.put(key, o);
              } else {
                  data.put(key, RawData.NULL);
              }
          }
          if (o == RawData.NULL) {
              return null;
          } else {
              return (T) o;
          }
      }
docs: Return configuration by {@link RythmConfigurationKey configuration key}
  
  @param key
  @param <T>
  @return the configured item