Invariant idea: "All includes get parsed successfully"

Another way to think of this is "the JSON Document object is told about all types of includes it should expect, so if we fail to parse any of the includes, a problem has occurred."

A potential reason for wanting to be able to ignore this invariant and succeed parsing anyway is that you anticipate other entity types getting included in a response in the future but do not yet know what they will look like or have a strategy for taking advantage of them on the clientside.

首先检查 JSON Document object 如何表示包含的类型，以及 include 解析目前如何强制执行所述不变量。在确定相关实现和测试之前，定义对无法识别或无法解析的 include 的预期行为，包括客户端如何知道解析已完成。