# Classes as Dependencies

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example

In the previous example, we were returning a `dict` from our dependency ("dependable"):

//// tab | Python 3.10+

```Python hl_lines="9"
{!> ../../docs_src/dependencies/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="11"

import org.codelibs.fess.exception.GsaConfigException;
import org.dbflute.optional.OptionalEntity;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class GsaConfigParser extends DefaultHandler {

    private static final Logger logger = LogManager.getLogger(GsaConfigParser.class);

    public static final String REGEXP = "regexp:";

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.testing.Helpers.NullsBeforeB;
import com.google.common.collect.testing.NavigableSetTestSuiteBuilder;
import com.google.common.collect.testing.TestStringSetGenerator;
import com.google.common.collect.testing.features.CollectionFeature;

import java.util.Set;
import java.util.SortedSet;
import junit.framework.TestCase;

/**
 * Class that contains nested abstract tests for filtered collection views, along with their
 * implementation helpers.
 *
 * @author Louis Wasserman
 */
/*
 * TODO(cpovirk): Should all the tests for filtered collections run under GWT, too? Currently, they
 * don't.
 */
public final class FilteredCollectionsTestUtil {

import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.Sets.newHashSet;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Collections.singletonMap;

import com.google.common.annotations.GwtCompatible;

	github.com/cyphar/filepath-securejoin v0.3.1 // indirect
	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 // indirect
	github.com/docker/distribution v2.8.3+incompatible // indirect
	github.com/docker/docker-credential-helpers v0.8.2 // indirect
	github.com/emicklei/go-restful/v3 v3.12.0 // indirect
	github.com/envoyproxy/protoc-gen-validate v1.1.0 // indirect
	github.com/exponent-io/jsonpath v0.0.0-20210407135951-1de76d718b3f // indirect

JSON Schema hatte keine `examples`, daher fügte OpenAPI seiner eigenen modifizierten Version ein eigenes `example`-Feld hinzu.

OpenAPI fügte auch die Felder `example` und `examples` zu anderen Teilen der Spezifikation hinzu:

import static com.google.common.collect.DiscreteDomain.integers;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.testing.Helpers.testCompareToAndEquals;
import static com.google.common.testing.SerializableTester.reserializeAndAssert;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;

 */

package com.google.common.collect.testing.google;

import static com.google.common.collect.BoundType.CLOSED;
import static com.google.common.collect.BoundType.OPEN;
import static com.google.common.collect.testing.Helpers.copyToList;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ADD;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;

What inspired **FastAPI**, how it compares to alternatives and what it learned from them.

## Intro

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

I have been avoiding the creation of a new framework for several years. First I tried to solve all the features covered by **FastAPI** using many different frameworks, plug-ins, and tools.