# Classes as Dependencies { #classes-as-dependencies }

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

## A `dict` from the previous example { #a-dict-from-the-previous-example }

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

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

			entry:    "src/dir/",
			dir:      "src/",
			sep:      slashSeparator,
			want:     true,
		},
		{
			testName: "deeper-file",
			entry:    "src/dir/somewhere.ext",
			dir:      "src/",
			sep:      slashSeparator,
			want:     false,
		},
		{
			testName: "deeper-dir",
			entry:    "src/dir/somewhere/",
			dir:      "src/",
			sep:      slashSeparator,
			want:     false,
		},
		{

</div>

That would work for most of the cases. 😎

You could use that command for example to start your **FastAPI** app in a container, in a server, etc.

## ASGI Servers { #asgi-servers }

Let's go a little deeper into the details.

FastAPI uses a standard for building Python web frameworks and servers called <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI is an ASGI web framework.

            final SmbTransportInternal trans = dc.unwrap(SmbTransportInternal.class);
            // the tconHostName is from the DC referral, that referral must be resolved
            // before following deeper ones. Otherwise e.g. samba will return a broken
            // referral.
            synchronized (trans) {
                try {
                    // ensure connected
                    trans.ensureConnected();

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                                for (Map.Entry<String, Object> deepEntry : deepMap.entrySet()) {
                                    String deepKey = nestedKey + "." + deepEntry.getKey();
                                    result = result.replace("${" + deepKey + "}", String.valueOf(deepEntry.getValue()));
                                }
                            }

import org.codelibs.fess.helper.PopularWordHelper;
import org.codelibs.fess.helper.ProcessHelper;
import org.codelibs.fess.helper.ProtocolHelper;
import org.codelibs.fess.helper.QueryHelper;
import org.codelibs.fess.helper.RelatedContentHelper;
import org.codelibs.fess.helper.RelatedQueryHelper;
import org.codelibs.fess.helper.RoleQueryHelper;
import org.codelibs.fess.helper.SambaHelper;

            System.clearProperty(Constants.FESS_CONFIG_PREFIX + arrayKey);
        }
    }

    // Test property key with dots
    public void test_get_propertyKeyWithDots() {
        String dottedKey = "deeply.nested.property.key";
        String dottedValue = "nested-value";

        System.setProperty(Constants.FESS_CONFIG_PREFIX + dottedKey, dottedValue);

        try {

import java.util.Objects;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Closer}.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CloserTest extends TestCase {

  private TestSuppressor suppressor;

  @Override
  protected void setUp() throws Exception {
    suppressor = new TestSuppressor();
  }

            }
        }
    }
}
```

### Custom OpenAPI *path operation* schema { #custom-openapi-path-operation-schema }

The dictionary in `openapi_extra` will be deeply merged with the automatically generated OpenAPI schema for the *path operation*.

So, you could add additional data to the automatically generated schema.