@Nested is used to signal that the annotated class is a nested, non-static test class (i.e., an inner class) that can share setup and state with an instance of its enclosing class. The enclosing class may be a top-level test class or another @Nested test class, and nesting can be arbitrarily deep.

@Nested test classes may be ordered via @TestClassOrder or a global ClassOrderer.

Test Instance Lifecycle

• A @Nested test class can be configured with its own Lifecycle mode which may differ from that of an enclosing test class.
• A @Nested test class cannot change the Lifecycle mode of an enclosing test class.