micrometer: Can't re-initialise TestObservationRegistry between tests

Apologies if I am missing something obvious but I’m failing to see a way to “reuse” a TestObservationRegistry across multiple tests in a test class.

Example:

@ExtendWith(SpringExtension.class)
@SpringBootTest
public class FooServiceTest {
  @Autowired
  private FooService fooService;

  @Autowired
  private TestObservationRegistry observationRegistry;

  @TestConfiguration
  static class ObservationConfiguration {
    @Bean
    TestObservationRegistry observationRegistry() {
      return TestObservationRegistry.create();
    }
  }

  @Test
  void testAddFooWithABar() {
    fooService.addWithBar();
    TestObservationRegistryAssert.assertThat(observationRegistry)
        .hasObservationWithNameEqualTo("foo.create")
        .that()
        .hasLowCardinalityKeyValue("isBar", "true");
  }

  @Test
  void testAddFooWithoutABar() {
    fooService.addWithoutBar();
    TestObservationRegistryAssert.assertThat(observationRegistry)
        .hasObservationWithNameEqualTo("foo.create")
        .that()
        .hasLowCardinalityKeyValue("isBar", "false");
  }
}

In the above, both tests call methods of the FooService which create similar Observations but with a slightly different KeyValue isBar.

When I run the test, one of the tests always fails because the hasObservationWithNameEqualTo() assertion gets the latest Observation matching the name foo.create, and the subsequent assertion on key value fails.

What is needed (I think) is some way of “clearing”/re-initialising the TestObservationRegistry between tests, but I can’t see any way of doing this short of annotating each test method with @DirtiesContext, which seems like a sledgehammer to crack a nut, and slows down test runs.

Or am I going about this the wrong way?