类分层结构
- java.lang.Object
- org.assertj.core.api.AbstractAssert<S,A> (implements org.assertj.core.api.Assert<S,A>) 
- org.assertj.core.api.AbstractObjectAssert<S,A> 
- org.springframework.boot.test.json.ObjectContentAssert<A>
 
 - org.springframework.boot.test.json.JsonContentAssert
 
 - org.assertj.core.api.AbstractObjectAssert<S,A> 
 - org.springframework.boot.test.json.AbstractJsonMarshalTester<T> 
- org.springframework.boot.test.json.GsonTester<T>
 - org.springframework.boot.test.json.JacksonTester<T>
 
 - org.springframework.boot.test.json.AbstractJsonMarshalTester.FieldInitializer<M>
 - org.springframework.boot.test.json.BasicJsonTester
 - org.springframework.boot.test.json.JsonContent<T> (implements org.assertj.core.api.AssertProvider<A>)
 - org.springframework.boot.test.json.ObjectContent<T> (implements org.assertj.core.api.AssertProvider<A>)
 
 - org.assertj.core.api.AbstractAssert<S,A> (implements org.assertj.core.api.Assert<S,A>)