* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps { #first-steps }

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

    }
  }

  @Test
  fun fullCallTimeoutDoesNotApplyOnceConnected() {
    enableProtocol(Protocol.HTTP_2)
    val body =
      MockSocketHandler()
        .sendResponse("response A\n")
        .sleep(750, TimeUnit.MILLISECONDS)
        .sendResponse("response B\n")
        .receiveRequest("request C\n")
        .exhaustResponse()
        .exhaustRequest()
    server.enqueue(
      MockResponse

  @SuppressWarnings({"GoodTime-ApiWithNumericTimeUnit", "GoodTime-DecomposeToPrimitive"})
  @IgnoreJRERequirement
  static long toNanosSaturated(Duration duration) {
    // Using a try/catch seems lazy, but the catch block will rarely get invoked (except for
    // durations longer than approximately +/- 292 years).
    try {
      return duration.toNanos();
    } catch (ArithmeticException tooBig) {

	if err != nil {
		t.Fatal(err)
	}

	for {
		_, err := restClient.DiskInfo(t.Context(), DiskInfoOptions{})
		if err == nil || errors.Is(err, errUnformattedDisk) {
			break
		}
		time.Sleep(time.Duration(rand.Float64() * float64(100*time.Millisecond)))
	}

	return restClient
}

func TestStorageRESTClientDiskInfo(t *testing.T) {
	restClient := newStorageRESTHTTPServerClient(t)

Let's check back those deployment concepts from before:

* Security - HTTPS
* Running on startup
* Restarts
* **Replication (the number of processes running)**
* Memory
* Previous steps before starting

Up to this point, with all the tutorials in the docs, you have probably been running a **server program**, for example, using the `fastapi` command, that runs Uvicorn, running a **single process**.

permissions:
  contents: read

jobs:
  replication-test:
    name: Advanced Tests with Go ${{ matrix.go-version }}
    runs-on: ubuntu-latest

    strategy:
      matrix:
        go-version: [1.24.x]

    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-go@v5
        with:
          go-version: ${{ matrix.go-version }}
          check-latest: true
      - name: Test Decom
        run: |

				logger.Info("Waiting for AuthN to be initialized.. (retrying in %s)", retryInterval)
			}
			if !authZInit {
				logger.Info("Waiting for AuthZ to be initialized.. (retrying in %s)", retryInterval)
			}
			time.Sleep(retryInterval)
			continue
		}

		break
	}

	// Initialize IAM store
	sys.Lock()

	sys.initStore(objAPI, etcdClient)

	// Initialize RoleARNs

        mockBhv.setTestData(testData);

        relatedQueryHelper.update();
        // Give a moment for async execution
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            // ignore
        }

        results = relatedQueryHelper.getRelatedQueries("test");
        assertEquals("updated", results[0]);
    }

        long initialAge = keyManager.getKeyAge(sessionId);
        assertTrue(initialAge >= 0 && initialAge < 100, "Initial age should be small");

        Thread.sleep(200);

        long laterAge = keyManager.getKeyAge(sessionId);
        assertTrue(laterAge >= 200, "Age should increase after delay");
    }

    @Test
    public void testKeyAgeNonExistent() {

          sb.append(DELIMITER_STRING);
        }
        sb.append(comp);
      }
      dummy ^= sb.toString().length();
    }
    return dummy;
  }

  /**
   * Similar to the above, but keeps a boolean flag rather than checking for the string accumulated
   * so far being empty. As a result, it does not have the above-mentioned bug.
   */
  @Benchmark
  int booleanIfFirst(int reps) {
    int dummy = 0;