{*../../docs_src/python_types/tutorial009.py hl[1,4] *}

Utiliser `Optional[str]` plutôt que `str` permettra à l'éditeur de vous aider à détecter les erreurs où vous supposeriez qu'une valeur est toujours de type `str`, alors qu'elle pourrait aussi être `None`.

#### Types génériques

Les types qui peuvent contenir des paramètres de types entre crochets, comme :

`v1.12.1`. The cgroups validator now throws an error instead of a warning if cgroups v1 is detected on the host and the provided KubeletVersion is `v1.35` or newer.
  
  kubeadm: Started using `k8s.io/system-validators` `v1.12.1` in `kubeadm` `v1.35`. During `kubeadm init`, `kubeadm join`, and `kubeadm upgrade`, the SystemVerification preflight check throws an error if cgroups v1 is detected and the detected `kubelet` version is `v1.35` or newer. For older versions of `kubelet`, a preflight warning...

    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()
    //

      result.writeDecimalLong(readVariableLengthLong())
    }
    return result.readUtf8()
  }

  /** Used for tags and subidentifiers. */
  private fun readVariableLengthLong(): Long {
    // TODO(jwilson): detect overflow.
    var result = 0L
    while (true) {
      val byteN = source.readByte().toLong() and 0xff
      if ((byteN and 0b1000_0000L) == 0b1000_0000L) {
        result = (result + (byteN and 0b0111_1111)) shl 7

    }

    /**
     * Determines whether the user identification cookie should be marked as secure.
     * Checks the configured secure setting or examines request headers to detect HTTPS.
     *
     * @return true if the cookie should be secure, false otherwise
     */
    protected boolean isSecureCookie() {
        if (cookieSecure != null) {
            return cookieSecure;
        }

  repositories are "really" offline, since offline mode is more of a behavior,
  and this will lead to counter-intuitive results. A different feature may exist
  unimplemented, which is to detect when the network is down and provide better
  feedback for that case. However, when offline mode is declared, nothing
  earmarked as remote should be accessed, regardless of whether it is actually
  a physically local resource.

        return;
      }
      // First, check whether var -> arg forms a cycle
      for (Type t = arg; t != null; t = mappings.get(TypeVariableKey.forLookup(t))) {
        if (var.equalsType(t)) {
          // cycle detected, remove the entire cycle from the mapping so that
          // each type variable resolves deterministically to itself.
          // Otherwise, an F -> T cycle will end up resolving both F and T

                artifacts, rootArtifact, managedVersions, collectionRequest, source, collectionFilter, listeners, null);

        // We have metadata retrieval problems, or there are cycles that have been detected
        // so we give this back to the calling code and let them deal with this information
        // appropriately.

        if (result.hasMetadataResolutionExceptions()

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

Having `str | None` will allow your editor to give you better support and detect errors.

///

## Additional validation { #additional-validation }

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

OkHttp 3.x Change Log
=====================

## Version 3.14.9

_2020-05-17_

 *  Fix: Don't crash when running as a plugin in Android Studio Canary 4.1. To enable
    platform-specific TLS features OkHttp must detect whether it's running in a JVM or in Android.
    The upcoming Android Studio runs in a JVM but has classes from Android and that confused OkHttp!


## Version 3.14.8

_2020-04-28_