后台数据为：返回类型没有设置（方式一）
1 String str = "["+ 2 "{ id:1, pId:0, name:\"可折腾的父节点 1\", t:\"我很普通，随便 展开/折叠 我吧\", open:false},"+ 3 "{ id:11, pId:1, name:\"叶子节点 - 1\", t:\"我老爸很普通，随便折腾他吧\"},"+ 4 "{ id:12, pId:1, name:\"可折腾的父节点 2\", t:\"我和我老爸都很普通，随便折腾我和他吧\", open: false},"+ 5 "{ id:121, pId:12, name:\"父节点 - 121\", t:\"我老爸很普通，随便折腾他吧\", open:true},"+ 6 "{ id:1211, pId:121, name:\"父节点 - 1211\", t:\"我老爸很普通，随便折腾他吧\", open:false},"+ 7 "{ id:1212, pId:1211, name:\"叶子节点 - 1212\", t:\"我老爸很普通，随便折腾他吧\"},"+ 8 "{ id:1213, pId:121, name:\"父节点 - 1213\", t:\"我老爸很普通，随便折腾他吧\", open:false},"+ 9 "{ id:1214, pId:1213, name:\"叶子节点 - 1214\", t:\"我老爸很普通，随便折腾他吧\"},"+ 10 "{ id:123, pId:12, name:\"叶子节点 - 23\", t:\"我老爸很普通，随便折腾他吧\"},"+ 11 "{ id:13, pId:1, name:\"叶子节点 - 3\", t:\"我老爸很普通，随便折腾他吧\"},"+ 12 "{ id:2, pId:1, name:\"无法折叠的父节点\", t:\"休想让我折叠起来...除非你用 expandAll 方法\", open:false, collapse:false},"+ 13 "{ id:21, pId:2, name:\"叶子节点2 - 1\", t:\"哈哈哈，我老爸NB吧，不能折叠吧？\"},"+ 14 "{ id:22, pId:21, name:\"叶子节点2 - 2\", t:\"哈哈哈，我老爸NB吧，不能折叠吧？\"},"+ 15 "{ id:23, pId:21, name:\"叶子节点2 - 3\", t:\"哈哈哈，我老爸NB吧，不能折叠吧？\"},"+ 16 "{ id:3, pId:2, name:\"无法展开的父节点\", t:\"就凭你也想展开我？难呀...嘿嘿, 除非你用 expandAll 方法\", open:false, expand:true},"+ 17 "{ id:31, pId:3, name:\"叶子节点3 - 1\", t:\"居然让你看到了...莫非你用了全部节点展开？\"},"+ 18 "{ id:32, pId:31, name:\"叶子节点3 - 2\", t:\"居然让你看到了...莫非你用了全部节点展开？\"},"+ 19 "{ id:33, pId:31, name:\"叶子节点3 - 3\", t:\"居然让你看到了...莫非你用了全部节点展开？\"},"+ 20 "{ id:4, pId:3, name:\"空空的父节点 1\", t:\"一无所有...除了我自己\", isParent:true, open:false}"+ 21 "]";