{* ../../docs_src/events/tutorial003.py hl[14:19] *}

The first part of the function, before the `yield`, will be executed **before** the application starts.

And the part after the `yield` will be executed **after** the application has finished.

### Async Context Manager { #async-context-manager }

      char c1 = seq.charAt(index++);
      if (c1 < Character.MIN_HIGH_SURROGATE || c1 > Character.MAX_LOW_SURROGATE) {
        // Fast path (first test is probably all we need to do)
        return c1;
      } else if (c1 <= Character.MAX_HIGH_SURROGATE) {
        // If the high surrogate was the last character, return its inverse
        if (index == end) {
          return -c1;
        }

      char c1 = seq.charAt(index++);
      if (c1 < Character.MIN_HIGH_SURROGATE || c1 > Character.MAX_LOW_SURROGATE) {
        // Fast path (first test is probably all we need to do)
        return c1;
      } else if (c1 <= Character.MAX_HIGH_SURROGATE) {
        // If the high surrogate was the last character, return its inverse
        if (index == end) {
          return -c1;
        }

      int n, @Nullable Entry<K, V>[] entryArray, boolean throwIfDuplicateKeys)
      throws BucketOverflowException {
    /*
     * The cast is safe: n==entryArray.length means that we have filled the whole array with Entry
     * instances, in which case it is safe to cast it from an array of nullable entries to an array
     * of non-null entries.
     */
    @SuppressWarnings("nullness")
    Entry<K, V>[] entries =

	}

	// This causes quorum failure verify.
	os.RemoveAll(disks[len(disks)-1])

	// Validate the last test.
	testCase := struct {
		bucketName    string
		objName       string
		inputData     []byte
		inputMeta     map[string]string
		inputDataSize int64
		// flag indicating whether the test should pass.
		shouldPass bool
		// expected error output.
		expectedMd5   string
		expectedError error
	}{

// To collect RX stats during "mc support perf net"
// RXSample holds the RX bytes for the duration between
// the last peer to connect and the first peer to disconnect.
// This is to improve the RX throughput accuracy.
type netPerfRX struct {
	RX                uint64    // RX bytes
	lastToConnect     time.Time // time at which last peer to connect to us
	firstToDisconnect time.Time // time at which the first peer disconnects from us

	pluginAuthnServiceSuccMaxRttMsMinuteMD   = NewCounterMD(pluginAuthnServiceSuccMaxRttMsMinute, "When plugin authentication is configured, returns maximum round-trip-time of successful requests in the last full minute")
	pluginAuthnServiceTotalRequestsMinuteMD  = NewCounterMD(pluginAuthnServiceTotalRequestsMinute, "When plugin authentication is configured, returns total requests count in the last full minute")

	}

	lastN = make([]log.Info, last)
	sys.RLock()
	sys.logBuf.Do(func(p any) {
		if p != nil {
			lg, ok := p.(log.Info)
			if ok && lg.SendLog(node, logKind) {
				lastN[cnt%last] = lg
				cnt++
			}
		}
	})
	sys.RUnlock()
	// send last n console log messages in order filtered by node
	if cnt > 0 {
		for i := range last {
			entry := lastN[(cnt+i)%last]
			if (entry == log.Info{}) {

   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(type::isInstance).map(type::cast)}.
   * This does perform a little more work than necessary, so another option is to insert an
   * unchecked cast at some later point:
   *
   * {@snippet :
   * @SuppressWarnings("unchecked") // safe because of ::isInstance check
   * ImmutableList<NewType> result =

          Object part = parts.next();
          if (part != null) {
            appendable.append(Joiner.this.toString(part));
            break;
          }
        }
        while (parts.hasNext()) {
          Object part = parts.next();
          if (part != null) {
            appendable.append(separator);
            appendable.append(Joiner.this.toString(part));
          }
        }