if os.IsNotExist(eErr) {
			return nil
		}
		return eErr
	}

	if err := target.send(eventData); err != nil {
		return err
	}

	return target.store.Del(key)
}

// Close - closes underneath connections to NATS server.
func (target *NATSTarget) Close() (err error) {
	close(target.quitCh)
	if target.stanConn != nil {
		// closing the streaming connection does not close the provided NATS connection.

Many packages that simplify it a lot have to make many compromises with the data model, database, and available features. And some of these packages that simplify things too much actually have security flaws underneath.

---

**FastAPI** doesn't make any compromise with any database, data model or tool.

It gives you all the flexibility to choose the ones that fit your project the best.

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

Underneath, the `open("./somefile.txt")` creates an object that is called a "Context Manager".

When the `with` block finishes, it makes sure to close the file, even if there were exceptions.

    So, it's important to put this **near the end** of the `Dockerfile`, to optimize the container image build times.

6. Set the **command** to use `fastapi run`, which uses Uvicorn underneath.

    `CMD` takes a list of strings, each of these strings is what you would type in the command line separated by spaces.

## Very Technical Details { #very-technical-details }

/// warning

You can probably skip this.

These are very technical details of how **FastAPI** works underneath.

If you have quite some technical knowledge (coroutines, threads, blocking, etc.) and are curious about how FastAPI handles `async def` vs normal `def`, go ahead.

///

dependency on elasticsearch will be substituted with the local elasticsearch
build. To add your plugin, create a directory called elasticsearch-extra as
a sibling of elasticsearch. Checkout your plugin underneath elasticsearch-extra
and the build will automatically pick it up. You can verify the plugin is
included as part of the build by checking the projects of the build.

  //    places you'll have monitor.enter()/monitor.leave() and other
  //    places you'll have guard.enter()/guard.leave() even though
  //    it's the same lock being acquired underneath. Always using
  //    monitor.enterXXX()/monitor.leave() will make it really clear
  //    which lock is held at any point in the code.
  //
  // 3. I think "enterWhen(notEmpty)" reads better than "notEmpty.enter()".

                    /* This is a key point. This is where we set the "tree" of this file which
                     * is like changing the rug out from underneath our feet.
                     */

would go, and broke off a bit of the edge with each hand.

  `And now which is which?' she said to herself, and nibbled a
little of the right-hand bit to try the effect:  the next moment
she felt a violent blow underneath her chin:  it had struck her
foot!

  She was a good deal frightened by this very sudden change, but
she felt that there was no time to be lost, as she was shrinking

would go, and broke off a bit of the edge with each hand.

  `And now which is which?' she said to herself, and nibbled a
little of the right-hand bit to try the effect:  the next moment
she felt a violent blow underneath her chin:  it had struck her
foot!

  She was a good deal frightened by this very sudden change, but
she felt that there was no time to be lost, as she was shrinking