# Unterabhängigkeiten { #sub-dependencies }

Sie können Abhängigkeiten erstellen, die **Unterabhängigkeiten** haben.

Diese können so **tief** verschachtelt sein, wie nötig.

**FastAPI** kümmert sich darum, sie aufzulösen.

## Erste Abhängigkeit, „Dependable“ { #first-dependency-dependable }

Sie könnten eine erste Abhängigkeit („Dependable“) wie folgt erstellen:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

 * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility">mostly
 *     source-compatible</a> since 4.0)
 */
@GwtCompatible
/*
 * The type parameter is <T> rather than <T extends @Nullable> so that we can use T in the
 * doEquivalent and doHash methods to indicate that the parameter cannot be null.
 */
@SuppressWarnings("UngroupedOverloads")
public abstract class Equivalence<T> {

SDK=iphonesimulator
PLATFORM=ios-simulator

if [ "$GOARCH" == "arm64" ]; then
	CLANGARCH="arm64"
else
	CLANGARCH="x86_64"
fi

SDK_PATH=`xcrun --sdk $SDK --show-sdk-path`

# cmd/cgo doesn't support llvm-gcc-4.2, so we have to use clang.
CLANG=`xcrun --sdk $SDK --find clang`

#
# Windows users contributing to Go will need to use a modern version
# of git and editors capable of LF line endings.
#
# Windows .bat files are known to have multiple bugs when run with LF
# endings, and so they are checked in with CRLF endings, with a test
# in test/winbatch.go to catch problems. (See golang.org/issue/37791.)
#
# We'll prevent accidental CRLF line endings from entering the repo

**FastAPI** knows what to do in each case and how to reuse the same object, so that all the background tasks are merged together and are run in the background afterwards:


{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain
 * platform classes unavailable. Then we construct a test suite so we can run the normal
 * AbstractFutureTest test methods in these degenerate classloaders.
 */

@NullUnmarked
public class AbstractFutureFallbackAtomicHelperTest extends TestCase {

tags_metadata = [
    {
        "name": "users",
        "description": "Operations with users. The **login** logic is also here.",
    },
    {
        "name": "items",
        "description": "Manage items. So _fancy_ they have their own docs.",
        "externalDocs": {
            "description": "Items external docs",
            "url": "https://fastapi.tiangolo.com/",
        },
    },
]

#include "../../../../../runtime/textflag.h"
// TODO: cover more instruction

TEXT foo(SB),DUPOK|NOSPLIT,$0
	JAL	1(PC)	//CALL 1(PC)	//00040054
	JAL	(R4)	//CALL (R4)	//8100004c
	// relocation in play so the assembled offset should be 0

    private ToStringHelper(String className) {
      this.className = checkNotNull(className);
    }

    /**
     * Configures the {@link ToStringHelper} so {@link #toString()} will ignore properties with null
     * value. The order of calling this method, relative to the {@code add()}/{@code addValue()}
     * methods, is not significant.
     *

		t.Fatalf("Unable to initialize new http request %s", err)
	}
	return req
}

// This is similar to mustNewRequest but additionally the request
// is signed with AWS Signature V4, fails if not able to do so.
func mustNewSignedRequest(method string, urlStr string, contentLength int64, body io.ReadSeeker, t *testing.T) *http.Request {
	req := mustNewRequest(method, urlStr, contentLength, body, t)
	cred := globalActiveCred