Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

These are the primary classes involved with establishing, sharing, and terminating connections:

<img src="/img/tutorial/body/image02.png">

## Editor support

In your editor, inside your function you will get type hints and completion everywhere (this wouldn't happen if you received a `dict` instead of a Pydantic model):

<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

<img src="/img/tutorial/body/image04.png">

			} else {
				kvsrc.Value = "off"
			}
		}
		res = append(res, madmin.IDPCfgInfo{
			Key:   kvsrc.Key,
			Value: kvsrc.Value,
			IsCfg: true,
			IsEnv: kvsrc.Src == config.ValueSourceEnv,
		})
	}

	if provCfg, exists := r.ProviderCfgs[cfgName]; exists && provCfg.RolePolicy != "" {
		// Append roleARN
		res = append(res, madmin.IDPCfgInfo{
			Key:   "roleARN",
			Value: provCfg.roleArn.String(),

          Reflection.newProxy(Map.class, new CheckSetUpInvocationHandler(map, setUpRan));
      return proxy;
    }
  }

  /**
   * Intercepts calls to a {@code Map} to check that {@code setUpRan} is true when they happen. Then
   * forwards the calls to the underlying {@code Map}.
   */
  private static class CheckSetUpInvocationHandler implements InvocationHandler, Serializable {
    private final Map<String, String> map;

	targets := []Target{}
	for _, tgt := range list.targets {
		targets = append(targets, tgt)
	}

	return targets
}

// List - returns available target IDs.
func (list *TargetList) List() []TargetID {
	list.RLock()
	defer list.RUnlock()

	keys := []TargetID{}
	for k := range list.targets {
		keys = append(keys, k)
	}

	return keys
}

which are unordered by happens before
(that is, neither <i>r</i> happens before <i>w</i>
nor <i>w</i> happens before <i>r</i>).
</p>

<p>
A <i>write-write data race</i> on memory location <i>x</i>
consists of two write-like memory operations <i>w</i> and <i>w'</i> on <i>x</i>,
at least one of which is non-synchronizing,
which are unordered by happens before.
</p>

<p>

   * Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners
   * after executing them.
   *

   * Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners
   * after executing them.
   *

   1. If the certificate is not yet expired, the `SecretManager` also can return a cache response. In practice, this would
       only happen in cases where Envoy were to re-request a resource, which is fairly rare.
   1. `SecretManager` can also read certificates from files. When this is configured, no CA client is used.

	}{ID: id})
	if err != nil {
		writeErrorResponseJSON(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	writeSuccessResponseJSON(w, b)
	// Notify peers to load rebalance.bin and start rebalance routine if they happen to be
	// participating pool's leader node
	globalNotificationSys.LoadRebalanceMeta(ctx, true)
}

func (a adminAPIHandlers) RebalanceStatus(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()