# Security Tools

When you need to declare dependencies with OAuth2 scopes you use `Security()`.

But you still need to define what is the dependable, the callable that you pass as a parameter to `Depends()` or `Security()`.

There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.

{!> ../../docs_src/query_params_str_validations/tutorial009.py!}
```

////

## Deprecating parameters

Now let's say you don't like this parameter anymore.

You have to leave it there a while because there are clients using it, but you want the docs to clearly show it as <abbr title="obsolete, recommended not to use it">deprecated</abbr>.

Then pass the parameter `deprecated=True` to `Query`:

This is normally the best way to contribute to the project.

## External Contributions

External contributions are very welcome and appreciated, including answering questions, submitting PRs, etc. 🙇‍♂️

- Don’t change public API lightly, avoid if possible, and include your reasoning in the PR if essential.  It causes pain for developers who use OkHttp and sometimes runtime errors.
- Favour a working external library if appropriate.  There are many examples of OkHttp libraries that can sit on top or hook in via existing APIs.
- Get working code on a personal branch with tests before you submit a PR.

   * xStats().populationVariance() > 0.0 || yStats().populationVariance() > 0.0}). The result is
   * guaranteed to be horizontal if there is variance in the {@code x} data but not the {@code y}
   * data, and vertical if there is variance in the {@code y} data but not the {@code x} data.
   *
   * <p>This fit minimizes the root-mean-square error in {@code y} as a function of {@code x}. This

// policy is the role's policy.
//
// - inherited from parent - this is the case for AssumeRole API, where the
// parent user is an actual real user with their own (permanent) credentials and
// policy association.
//
// - inherited from "virtual" parent - this is the case for AssumeRoleWithLDAP
// where the parent user is the DN of the actual LDAP user. The parent user

   * least decide on a policy for when to use which.
   */

  /**
   * Returns the value associated with the specified key, or {@code null} if there is no such value.
   *
   * <p>Specifically, if any range in this range map contains the specified key, the value
   * associated with that range is returned.
   */
  @CheckForNull
  V get(K key);

  /**

 * appropriate {@link DiscreteDomain} to {@link ContiguousSet#create}.
 *
 * <h3>Types of ranges</h3>
 *
 * <p>Each end of the range may be bounded or unbounded. If bounded, there is an associated
 * <i>endpoint</i> value, and the range is considered to be either <i>open</i> (does not include the
 * endpoint) or <i>closed</i> (includes the endpoint) on that side. With three possibilities on each

import org.apache.maven.api.services.MavenException;

/**
 * Represents an exception that occurs during the parsing of Maven command-line arguments.
 * This exception is typically thrown when there are user errors in the command-line input,
 * such as invalid arguments or references to missing files. When this exception is thrown,
 * it indicates that the Maven execution should be stopped and the user should correct the issue.

import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.annotations.Nonnull;

/**
 * <p>In Maven, repositories are locations where project artifacts (such as JAR files, POM files, and other
 * resources) are stored and retrieved. There are two primary types of repositories:
 * {@linkplain LocalRepository local repositories} and
 * {@linkplain RemoteRepository remote repositories}.</p>
 *