/** All pipe instances are busy */
    int NT_STATUS_PIPE_BUSY = 0xC00000ae;
    /** No process is on the other end of the pipe */
    int NT_STATUS_PIPE_DISCONNECTED = 0xC00000b0;
    /** The pipe is being closed */
    int NT_STATUS_PIPE_CLOSING = 0xC00000b1;
    /** Waiting for a process to open the other end of the pipe */
    int NT_STATUS_PIPE_LISTENING = 0xC00000b3;
    /** The file that was specified is a directory */

# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

#### More details { #more-details }

Let's say your file is named `myapp.py`.

If you run it with:

<div class="termy">

    // a multithreaded environment for a couple of reasons:
    //
    // 1. Subscribers to events posted on different threads can be interleaved with each other
    //    freely. (A event on one thread, B event on another could yield any of
    //    [a1, a2, a3, b1, b2], [a1, b2, a2, a3, b2], [a1, b2, b3, a2, a3], etc.)
    // 2. It's possible for subscribers to actually be dispatched to in a different order than they

 * possibly run in another thread.
 *
 * <p>{@code UncheckedExecutionException} is intended as an alternative to {@code
 * ExecutionException} when the exception thrown by a task is an unchecked exception. However, it
 * may also wrap a checked exception in some cases.
 *
 * <p>When wrapping an {@code Error} from another thread, prefer {@link ExecutionError}. When

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).

       * cause set to the underlying exception (which may be from another thread). If we someday
       * learn that some other exception besides IllegalArgumentException is common, then we could
       * add another special case to throw an instance of it, too.
       */
      throw e;
    }
  }

  private static ImmutableList<Method> getAnnotatedMethodsNotCached(Class<?> clazz) {

    return delegate.isEmpty();
  }

  @Override
  public Object[] toArray() {
    return delegate.toArray();
  }

  @Override
  public <T extends @Nullable Object> T[] toArray(T[] other) {
    return delegate.toArray(other);
  }

  @Override
  public String toString() {
    return delegate.toString();
  }

  // TODO(cpovirk): equals(), as well, in case it's any faster than Sets.equalsImpl?

  @Override

    expectedEvents += "ConnectionReleased"
    expectedEvents += "CallEnd"
    assertThat(listener.recordedEventTypes()).isEqualTo(expectedEvents)

    // Confirm that the connection pool was not corrupted by making another call.
    makeSimpleCall()
  }

  /**
   * If the server returns a full response, it doesn't really matter if the HTTP/2 stream is reset.
   * Attempts to write the request body fails fast.
   */
  @Test

          if (toSkip == 0L) break
          source.skip(toSkip)
        }
        source.skip(crlfDashDashBoundary.size.toLong())
      }

      // Read either \r\n or --\r\n to determine if there is another part.
      var whitespace = false
      afterBoundaryLoop@while (true) {
        when (source.select(afterBoundaryOptions)) {
          0 -> {
            // "\r\n": We've found a new part.
            partCount++