check_success: (Function) function that takes one argument and returns a
      boolean. Should return True if the value provided is considered valid. May
      contain a complex error message if error_msg does not provide enough
      information. In that case, set suppress_default_error to True.
    error_msg: (String) String with one and only one '%s'. Formatted with each

     */
    public synchronized Proxy getActiveProxy() {
        if (activeProxy == null) {
            java.util.List<Proxy> proxies = getProxies();
            if (proxies != null && !proxies.isEmpty()) {
                for (Proxy proxy : proxies) {
                    if (proxy.isActive()) {
                        activeProxy = proxy;
                        break;
                    }

import gradlebuild.basics.util.ReproduciblePropertiesWriter
import org.gradle.api.DefaultTask
import org.gradle.api.file.DirectoryProperty
import org.gradle.api.logging.Logger
import org.gradle.api.provider.Property
import org.gradle.api.provider.Provider
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.Optional
import org.gradle.api.tasks.OutputDirectory
import org.gradle.api.tasks.TaskAction

Having `str | None` will allow your editor to give you better support and detect errors.

///

## Additional validation { #additional-validation }

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated` { #import-query-and-annotated }

To achieve that, first import:

* `Query` from `fastapi`
* `Annotated` from `typing`

```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///

Then you could call that Python program:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console

	metaCh  chan *MetaValue
	err     error

	// follow line position to add context to errors
	lineNo    int
	lineStart int64
}

// NewDecoder creates new Decoder to read JSON values at the provided
// emitDepth from the provider io.Reader.
// If emitDepth is < 0, values at every depth will be emitted.
func NewDecoder(r io.Reader, emitDepth int) *Decoder {
	d := &Decoder{
		scanner:   newScanner(r),
		emitDepth: emitDepth,

      <version>1.0</version>
      <scope>compile</scope>
    </dependency>

    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>scope-provided</artifactId>
      <version>1.0</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>maven-inherited</groupId>
      <artifactId>scope-default</artifactId>
      <version>1.0</version>
    </dependency>

    encoding was used by plugins)

    * <<<$\{project.reporting.outputEncoding\}>>> for
    {{{https://cwiki.apache.org/confluence/display/MAVENOLD/Reporting+Encoding+Configuration}reporting output files encoding}}
    (defaults to <<<UTF-8>>> since Maven 4.0.0, no default value was provided in Maven 3.x, plugins usually defaulting
    to <<<UTF-8>>>)

  in {{{./apidocs/org/apache/maven/lifecycle/providers/packaging/package-summary.html}<<<org.apache.maven.lifecycle.providers.packaging>>>}} package
  because they are specific for each packaging:

%{toc|fromDepth=2}

  Versions of the plugins are shared in a few constants:

%{snippet|id=versions|file=${project.basedir}/src/main/java/org/apache/maven/lifecycle/providers/packaging/AbstractLifecycleMappingProvider.java}

# Dependencies { #dependencies }

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }