If there were any background tasks (documented later), they will run *after* all the middleware.

## Create a middleware

To create a middleware you use the decorator `@app.middleware("http")` on top of a function.

The middleware function receives:

* The `request`.
* A function `call_next` that will receive the `request` as a parameter.

You should do it after adding all your *path operations*.

```Python hl_lines="2  12-21  24"
{!../../../docs_src/path_operation_advanced_configuration/tutorial002.py!}
```

!!! tip
    If you manually call `app.openapi()`, you should update the `operationId`s before that.

/**
 * CompactLinkedHashSet is an implementation of a Set, which a predictable iteration order that
 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)
 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a

     */
    @Nonnull
    Optional<RemoteRepository> getRepository();

    /**
     * Traverses this node and potentially its children using the specified visitor.
     *
     * @param visitor the visitor to call back, must not be {@code null}
     * @return {@code true} to visit siblings nodes of this node as well, {@code false} to skip siblings
     */
    boolean accept(@Nonnull NodeVisitor visitor);

    /**

		if err != nil {
			return err
		}
	}

	if val.IsNull() {
		// E.g. the column or field does not exist in the
		// record - in all such cases the aggregation is not
		// updated.
		return nil
	}

	argVal := val
	if funcName != aggFnCount {
		// All aggregation functions, except COUNT require a
		// numeric argument.

		// Here, we diverge from Amazon S3 behavior by

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Helper class for creating {@link CacheBuilder} instances with all combinations of several sets of
 * parameters.
 *
 * @author mike nonemacher
 */
class CacheBuilderFactory {
  // Default values contain only 'null', which means don't call the CacheBuilder method (just give
  // the CacheBuilder default).

 * until [nextPart] returns null. After calling [nextPart] any preceding parts should not be read.
 *
 * Typical use loops over the parts in sequence:
 *
 * ```kotlin
 * val response: Response = call.execute()
 * val multipartReader = MultipartReader(response.body!!)
 *
 * multipartReader.use {
 *   while (true) {
 *     val part = multipartReader.nextPart() ?: break
 *     process(part.headers, part.body)
 *   }

    if:
      - {{ ('misc_labels' | isEnabledAutomation(pr)) }}
      - {{ is.formatting }}
    run:
      - action: add-label@v1
        args:
          label: 'a:chore'
      - action: approve@v1

  # Call out PRs that change the build script (and will be longer to checkout and review)
  label_build_script_change:
    if:
      - {{ ('misc_labels' | isEnabledAutomation(pr)) }}
      - {{ is.build_script_change }}
    run:

import okhttp3.internal.toHostHeader
import okio.GzipSource
import okio.buffer

/**
 * Bridges from application code to network code. First it builds a network request from a user
 * request. Then it proceeds to call the network. Finally it builds a user response from the network
 * response.
 */
class BridgeInterceptor(private val cookieJar: CookieJar) : Interceptor {
  @Throws(IOException::class)

 * support them). All optional multimap methods are supported, and all returned views are
 * modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedSortedSetMultimap}.
 *