When you add multiple middlewares using either `@app.middleware()` decorator or `app.add_middleware()` method, each new middleware wraps the application, forming a stack. The last middleware added is the *outermost*, and the first is the *innermost*.

On the request path, the *outermost* middleware runs first.

On the response path, it runs last.

For example:

```Python
app.add_middleware(MiddlewareA)
app.add_middleware(MiddlewareB)
```

    for (int i = 0; i < 100000; i++) {
      SettableFuture<String> curr = SettableFuture.create();
      prev.setFuture(curr);
      prev = curr;
    }
    // orig represents the 'outermost' future
    assertThat(orig.toString())
        .contains("Exception thrown from implementation: class java.lang.StackOverflowError");
  }

  public void testSetFuture_misbehavingFutureThrows() throws Exception {

    for (int i = 0; i < 100000; i++) {
      SettableFuture<String> curr = SettableFuture.create();
      prev.setFuture(curr);
      prev = curr;
    }
    // orig represents the 'outermost' future
    assertThat(orig.toString())
        .contains("Exception thrown from implementation: class java.lang.StackOverflowError");
  }

  public void testSetFuture_misbehavingFutureThrows() throws Exception {