In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

import (
	"context"
	"fmt"
	"net/http"
	"net/url"
	"os"
	"testing"
	"time"
)

func niceError(code APIErrorCode) string {
	// Special-handle ErrNone
	if code == ErrNone {
		return "ErrNone"
	}

	return fmt.Sprintf("%s (%s)", errorCodes[code].Code, errorCodes[code].Description)
}

func TestDoesPolicySignatureMatch(t *testing.T) {
	_, fsDir, err := prepareFS(t.Context())
	if err != nil {
		t.Fatal(err)

  parsed_args = parser.parse_args()
  if not parsed_args.print and not parsed_args.xml_out_path:
    raise TypeError('`--print` or `--xml-out-path` must be specified')

  return parsed_args


def parse_log(file_path: str,
              verbose: bool = False) -> ResultDictType:
  """Finds ResultStore links, and tries to determine their status."""

chrome.omnibox.onInputEntered.addListener(function(t) {
  var url = urlForInput(t);
  if (url) {
    chrome.tabs.query({ "active": true, "currentWindow": true }, function(tab) {
      if (!tab) return;
      chrome.tabs.update(tab.id, { "url": url, "selected": true });
    });
  }

// such as transfer rate and objects queued.
func loadClusterReplicationMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	st := globalReplicationStats.Load()
	if st == nil {
		return nil
	}

	qs := st.getNodeQueueStatsSummary()

	qt := qs.QStats
	m.Set(replicationAverageQueuedBytes, float64(qt.Avg.Bytes))
	m.Set(replicationAverageQueuedCount, float64(qt.Avg.Count))

        assertEquals("line1\nline2", result[0]);
        assertEquals("normal", result[1]);

        // Carriage return
        value = "\"with\rcarriage\",return";
        result = KuromojiCSVUtil.parse(value);
        assertEquals(2, result.length);
        assertEquals("with\rcarriage", result[0]);
        assertEquals("return", result[1]);

        // Unicode characters
        value = "\"日本語\",\"한국어\",\"中文\"";

        assertEquals("\\", request.getPath());

        // Test empty path
        request.setPath("");
        assertEquals("\\", request.getPath());
    }

    @Test
    @DisplayName("Test getPath returns correct formatted path")
    void testGetPath() {
        request = new Smb2CreateRequest(mockConfig, "share\\file.txt");
        assertEquals("\\share\\file.txt", request.getPath());

```Python hl_lines="1"
async def get_burgers(number: int):
    # burgerleri oluşturmak için asenkron birkaç iş
    return burgers
```

...`def` yerine:

```Python hl_lines="2"
# bu kod asenkron değil
def get_sequential_burgers(number: int):
    # burgerleri oluşturmak için senkron bırkaç iş
    return burgers
```

 *
 * @param <T> The interface whose features are to be enumerated.
 * @author George van den Driessche
 */
@GwtCompatible
public interface Feature<T> {
  /** Returns the set of features that are implied by this feature. */
  Set<Feature<? super T>> getImpliedFeatures();

$ATTEMPTS -gt $LIMIT ]; then exit 1 ; fi ; sleep 2 ; # 1 second intervals between attempts $MC_COMMAND ; STATUS=$? ; done ; set -e ; # reset `e` as active return 0 } # checkBucketExists ($bucket) # Check if the bucket exists, by using the exit code of `mc ls` checkBucketExists() { BUCKET=$1 CMD=$(${MC} ls myminio/$BUCKET > /dev/null 2>&1) return $? } # createBucket ($bucket, $policy, $purge) # Ensure bucket exists, purging if asked to createBucket() { BUCKET=$1 POLICY=$2 PURGE=$3 VERSIONING=$4 # Purge...