derived.cancel(false);
    assertTrue(secondary.isCancelled());
    assertFalse(secondary.wasInterrupted());
    fallback.verifyCallCount(1);
  }

  // test of a bogus implementation
  @SuppressWarnings({"AsyncFunctionReturnsNull", "nullness"})
  @J2ktIncompatible // Nullability
  public void testCatchingAsync_nullInsteadOfFuture() throws Exception {

    derived.cancel(false);
    assertTrue(secondary.isCancelled());
    assertFalse(secondary.wasInterrupted());
    fallback.verifyCallCount(1);
  }

  // test of a bogus implementation
  @SuppressWarnings({"AsyncFunctionReturnsNull", "nullness"})
  @J2ktIncompatible // Nullability
  public void testCatchingAsync_nullInsteadOfFuture() throws Exception {

    // The inclusion of a body in the response to a CONNECT is key to reproducing b/6754912.
    server.enqueue(
      MockResponse
        .Builder()
        .inTunnel()
        .body("bogus proxy connect response content")
        .build(),
    )
    server.enqueue(MockResponse(body = "response"))

    // Configure a single IP address for the host and a single configuration, so we only need one