You will see examples of this in the next chapters, about relational and NoSQL databases, security, etc.

## **FastAPI** compatibility

The simplicity of the dependency injection system makes **FastAPI** compatible with:

* all the relational databases
* NoSQL databases
* external packages
* external APIs
* authentication and authorization systems
* API usage monitoring systems

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 * or obfuscated with tools like R8 or ProGuard. In such cases it'll return a longer string like
 * "com.example.shaded.okhttp3.OkHttp". In large applications it's possible to have multiple OkHttp
 * instances; this makes it clear which is which.
 */
@JvmField
internal val okHttpName: String =
  OkHttpClient::class.java.name.removePrefix("okhttp3.").removeSuffix("Client")

@Suppress("NOTHING_TO_INLINE")

        Collections.addAll(trustedCertificates, *platformTrustManager.acceptedIssuers)
      }

    /**
     * Configures this to not authenticate the HTTPS server on to [hostname]. This makes the user
     * vulnerable to man-in-the-middle attacks and should only be used only in private development
     * environments and only to carry test data.
     *

    cat <<EOF
Please rename files so there are no repeats. For example, README.md and
Readme.md would be the same file on Windows. In this test, you would get a
warning for "readme.md" because it makes everything lowercase. There are
repeats of these filename(s) with different casing:
EOF
    find . | tr '[A-Z]' '[a-z]' | sort | uniq -d | tee $BATS_FILE_TMPDIR/repeats
    [[ ! -s $BATS_FILE_TMPDIR/repeats ]]
}

`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

///

### Use the form data

    Original Software, to make, have made, use, practice, sell, and
    offer for sale, and/or otherwise dispose of the Original Software
    (or portions thereof).

    (c) The licenses granted in Sections 2.1(a) and (b) are effective on
    the date Initial Developer first distributes or otherwise makes the
    Original Software available to a third party under the terms of this
    License.

    (almost) opaque type for the user level programs.  The file and
    this data structure is not standardized.  Don't rely on it.  It can
@@ -41,4 +44,6 @@ typedef struct __locale_struct
 /* POSIX 2008 makes locale_t official.  */
 typedef __locale_t locale_t;
 
+#endif /* bits/types/__locale_t.h */
+
 #endif /* xlocale.h */
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index d1cb3dd..30482a1 100644

And we know that editors can't provide a lot of support (like completion) for `dict`s, because they can't know their keys and value types.

We can do better...

## What makes a dependency

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

      } catch (e: IOException) {
        carrier.noNewExchanges()
        responseBodyComplete()
        throw e
      }
    }

    /**
     * Closes the cache entry and makes the socket available for reuse. This should be invoked when
     * the end of the body has been reached.
     */
    fun responseBodyComplete() {
      if (state == STATE_CLOSED) return