Documentation that describes the Spring ContextConfiguration Evaluation Order with Inheritance?

Question

Lets say I have the following setup for 2 test classes in a SpringBoot Project

class Config1 {
  @Bean
  public MyObject myObject() {
    return Mockito.mock(myObject.class);
  }
}

class Config2 {
  @Bean
  public MyObject myObject() {
    return new MyObject();
  }
}

@ContextConfiguration(classes = {Config1.class, Config2.class})
class Parent {
 ....
}

class Test1 extends Parent {
  @AutoWired
  private MyObject myObject; // Instance of MyObject rather than a Mock
  ....
}

class Config3 extends Config1 {
  ....
}

@ContextConfiguration(classes = Config3.class)
class Test2 extends Parent {
  @AutoWired
  private MyObject myObject; // Instance of a Mock rather than MyObject
  ....
}

As the comments mention, for Test1 the instance of MyObject comes from Config2, while Test2 receives the Config3 (inherited via Config1) mocked instance of MyObject.

The rule this seems to follow is the last evaluated config wins. i.e. If Parent was defined as

@ContextConfiguration(classes = {Config2.class, Config1.class})
class Parent {

Then only the Mock would be used (I assume).

Where are the the rules, that define the evaluation order, for the @ContextConfiguration described?

There appear to be flags to control whether inheritance is ignored. See https://www.logicbig.com/tutorials/spring-framework/spring-core/test-configuration-inheritance.html. But I did not find anything to describe the evaluation order.

PS: Apologies for the convoluted sample code. It's a simplified version of something I came across.