Caching json strings in expensive objects

We are trying to optimize gson resource usage in our servers.
Most of our requests CPU's are taking 200ms just doing gson serialization.

We've done a great progress by using the following method:
http://stackoverflow.com/a/30811549/410293

Although, we can't figure out how to make this work when the object is nested into a JsonWritterTree. I was hoping you had some insight on how to possibly nest a string into the JsonWritterTree.write without AssertError.

首先复现所报告的 Gson 序列化案例：缓存的 JSON 字符串嵌套在 JsonWritterTree 中，并确定 JsonWritterTree.write 在哪里引发 AssertionError。将其与链接的 Stack Overflow 方法进行比较；当嵌套的缓存字符串能够在不触发断言的情况下得到支持，同时保留预期的序列化行为时，即表示完成。

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