graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

This way you write shared code once and **FastAPI** takes care of calling it for your *path operations*.

/// check

Notice that you don't have to create a special class and pass it somewhere to **FastAPI** to "register" it or anything similar.

* Data "<abbr title="converting the string that comes from an HTTP request into Python data">parsing</abbr>"
* Data validation
* API annotation and automatic documentation

And you only have to declare them once.

  public TestThread(L lockLikeObject, String threadName) {
    super(threadName);
    this.lockLikeObject = checkNotNull(lockLikeObject);
    start();
  }

  /*
   * TODO: b/318391980 - Once we test only under Java 20 and higher, avoid calling Thread.stop. As
   * of Java 20, it always throws an exception, and as of Java 26, the method does not even exist.
   * For now, we continue using it to clean up under older JDKs.

   * down to replace the element at {@code index}. This fact is used by iterator.remove so as to
   * visit elements during a traversal once and only once.
   */
  @VisibleForTesting
  @CanIgnoreReturnValue
  @Nullable MoveDesc<E> removeAt(int index) {
    checkPositionIndex(index, size);
    modCount++;
    size--;
    if (size == index) {

                    doneLatch.countDown();
                }
            }).start();
        }

        startLatch.countDown();
        doneLatch.await();

        // Verify all items were polled exactly once
        assertEquals(itemsPerThread * numThreads, totalPolled.get());
        assertEquals(itemsPerThread * numThreads, allUrls.size());

        urlQueueService.delete(sessionId);
    }

    this.function = checkNotNull(function);
  }

  @Override
  @SuppressWarnings({
    "CatchingUnchecked", // sneaky checked exception
    "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
  })
  public final void run() {
    @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
    @RetainedLocalRef F localFunction = function;

### Die `Settings` nur einmal laden mittels `lru_cache` { #creating-the-settings-only-once-with-lru-cache }

	// Is MINIO_SYNC_BOOT set?
	globalEnableSyncBoot bool

	// Contains NIC interface name used for internode communication
	globalInternodeInterface     string
	globalInternodeInterfaceOnce sync.Once

	// Set last client perf extra time (get lock, and validate)
	globalLastClientPerfExtraTime int64

	// Captures all batch jobs metrics globally
	globalBatchJobsMetrics batchJobMetrics

        SmbTreeImpl tree = mock(SmbTreeImpl.class);
        doReturn(tree).when(session).getSmbTree(eq("LOGON$"), isNull());

        // Act
        session.treeConnectLogon();

        // Assert: treeConnect invoked once with null params
        verify(tree, times(1)).treeConnect(isNull(), isNull());
        // Close of try-with-resources should call close on the mock
        verify(tree, times(1)).close();
    }

    @Test

        assertEquals("file1.txt", result.getName());

        assertFalse(iterator.hasNext(), "Should not have more elements");

        // Verify delegate.next() was only called once
        verify(mockDelegate, times(1)).next();
    }

    /**
     * Test constructor initializes correctly.
     */
    @Test
    void testConstructorInitialization() {
        // Given