table group ，子类弗雷相同属性

tableview.estimatedSectionHeaderHeight = 0;

tableview.estimatedSectionFooterHeight = 0;

http://blog.csdn.net/leemin_ios/article/details/49799479

@dynamic delegate;

• (void)setDelegate:(id)delegate {
  [super setDelegate:delegate];
  }
• (id)delegate {
  return (id)[super delegate];
  }

http://blog.csdn.net/u011363981/article/details/71499742

http://blog.csdn.net/jeffasd/article/details/50475608

http://www.cocoachina.com/bbs/read.php?tid=1693250