"No mapping between account names and security IDs was done.", "The security ID structure is invalid.",
            "The file system is full.", "All pipe instances are busy.", "All pipe instances are busy.", "The pipe state is invalid.",
            "All pipe instances are busy.", "No process is on the other end of the pipe.", "The pipe is being closed.",

# OpenAPI Webhooks { #openapi-webhooks }

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

            "No mapping between account names and security IDs was done.", "The security ID structure is invalid.",
            "All pipe instances are busy.", "All pipe instances are busy.", "The pipe state is invalid.", "All pipe instances are busy.",
            "No process is on the other end of the pipe.", "The pipe is being closed.",

          }
        }
      }
      return@FutureTask null
    }
  }

  /** Returns once all stream actions complete successfully. */
  fun awaitSuccess() {
    val futureTask =
      results.poll(5, TimeUnit.SECONDS)
        ?: throw AssertionError("no onRequest call received")
    futureTask.get(5, TimeUnit.SECONDS)
  }

    // Verify that the listener executed in a reasonable amount of time.
    Assert.assertTrue(countDownLatch.await(1L, SECONDS));

    try {
      future.get();
      Assert.fail("This call was supposed to throw an ExecutionException");
    } catch (ExecutionException expected) {
      Assert.assertSame(expectedCause, expected.getCause());
    }
  }

  public void assertTimeout() throws Exception {

     * Provides a hint for how many values will be associated with each key newly added to the
     * builder after this call. This does not change semantics, but may improve performance if
     * {@code expectedValuesPerKey} is a good estimate.
     *
     * <p>This may be called more than once; each newly added key will use the most recent call to
     * {@link #expectedValuesPerKey} as its hint.
     *

    @Test
    public void test_closeMethodExists() {
        // Test that close method is available (inherited from parent)
        try {
            // Just verify the method exists, don't actually call it
            crawlerEngineClient.getClass().getMethod("close");
            assertTrue(true);
        } catch (NoSuchMethodException e) {
            fail("close method should exist");
        }
    }

    Method method = getTestSubscriberMethod("recordingMethod");
    Subscriber subscriber = Subscriber.create(bus, this, method);

    subscriber.invokeSubscriberMethod(FIXTURE_ARGUMENT);

    assertTrue("Subscriber must call provided method", methodCalled);
    assertTrue(
        "Subscriber argument must be exactly the provided object.",
        methodArgument == FIXTURE_ARGUMENT);
  }

	return &Reader{
		args:       args,
		decoder:    d,
		valueCh:    d.Stream(),
		readCloser: readCloser,
	}
}

// syncReadCloser will wrap a readcloser and make it safe to call Close while
// reads are running.
type syncReadCloser struct {
	rc io.ReadCloser
	mu sync.Mutex
}

func (pr *syncReadCloser) Read(p []byte) (n int, err error) {

Actually, all (or most) of the web frameworks work in this same way.

You never call those functions directly. They are called by your framework (in this case, **FastAPI**).