But you can have thousands of endpoints (*path operations*) using the same security system.

And all of them (or any portion of them that you want) can take advantage of re-using these dependencies or any other dependencies you create.

And all these thousands of *path operations* can be as small as 3 lines:

//// tab | Python 3.10+

```Python hl_lines="30-32"
{!> ../../docs_src/security/tutorial002_an_py310.py!}
```

- Seal/Unmount one/some master keys. That will lock all SSE-S3 encrypted objects protected by these master keys. All these objects can not be decrypted as long as the key(s) are sealed.

      if (!GUAVA_PACKAGES.contains(info.getPackageName())) {
        continue;
      }
      if (info.getName().endsWith("GwtSerializationDependencies")) {
        continue; // These classes exist only for the GWT compiler, not to be used.
      }
      if (
      /*
       * At least one of the classes nested inside TypeResolverTest triggers a bug under older JDKs:

	entries := []string{}
	for i := 0; i < 10; i++ {
		name := fmt.Sprintf("file-%d", i)
		if err := os.WriteFile(filepath.Join(dir, name), []byte{}, os.ModePerm); err != nil {
			// For cleanup, its required to add these entries into test results.
			testResults = append(testResults, result{dir, entries})
			t.Fatalf("Unable to create file, %s", err)
		}
		entries = append(entries, name)
	}

# Request Parameters

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python

// CHECKSTYLE_OFF: RegexpHeader|LineLength
/**
 * XML reader and writer classes for Maven POM, generated from <code>maven.mdo</code> model.
 * These classes use
 * <a href="https://codehaus-plexus.github.io/plexus-utils/apidocs/org/codehaus/plexus/util/xml/pull/package-summary.html">plexus-utils'
 * XML Pull Parser API</a> for their internal XML handling and

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

# How To - Recipes

Here you will see different recipes or "how to" guides for **several topics**.

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

/// tip

   * only become known via CAS failures, convergence can be slow,
   * and because threads are typically not bound to CPUS forever,
   * may not occur at all. However, despite these limitations,
   * observed contention rates are typically low in these cases.
   *
   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where

This practice is common enough that it has a name, these environment variables are commonly placed in a file `.env`, and the file is called a "dotenv".

/// tip

A file starting with a dot (`.`) is a hidden file in Unix-like systems, like Linux and macOS.

But a dotenv file doesn't really have to have that exact filename.

///