code: @SuppressWarnings("unchecked")
      public <T> Entity<T> getEntity(Class<T> classOfT) {
          Entity<?> re = map.get(classOfT);
          if (null == re || !re.isComplete()) {
              synchronized (map) {
                  re = map.get(classOfT);
                  if (null == re) {
                      re = maker.make(classOfT);
                  }
              }
          }
          return (Entity<T>) re;
      }
docs: 根据类型获取实体
  
  @param classOfT
  实体类型
  @return 实体