And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first

You could still use most of the features in **FastAPI** with the knowledge from the main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank}.

And the next sections assume you already read it, and assume that you know those main ideas.

## External Courses

# Note: in awk, "print $N" prints the Nth "field", where fields are strings separated
# by whitespace. The flag "-F<x>" changes the behavior such that fields are now strings
# separated by the character <x>. Therefore, -F\' (escaped single quote) means that field
# $2 in <Tensor'flow'> is <flow>. This is useful for reading string literals like below.

## Decision

We do not introduce new public API methods that include Groovy types in their signatures.
Existing Groovy methods will not be removed immediately.

## Status

ACCEPTED

## Consequences

* If we would have used `Closure`, we must instead use `Action<T>`, `Spec<T>`, `Callable<T>`, or `Transformer<OUT, IN>`.
* We need to ensure all APIs that are exposed in the Groovy DSL go through runtime decoration.

 * want their output to be non-null in operations like `stream.map(myConverter)`, and we can
 * guarantee that as long as we also require the input type to be non-null[*] (which is a
 * requirement that existing callers already fulfill).
 *
 * Disclaimer: Part of the reason that callers are so well adapted to `Function<A, B>` may be that
 * that is how the signature looked even prior to this comment! So naturally any change can break

    if (obj instanceof Subscriber) {
      Subscriber that = (Subscriber) obj;
      // Use == so that different equal instances will still receive events.
      // We only guard against the case that the same object is registered
      // multiple times
      return target == that.target && method.equals(that.method);
    }
    return false;
  }

  /**

      if (obj == this) {
        return true;
      }
      if (obj instanceof Wrapper) {
        Wrapper<?> that = (Wrapper<?>) obj; // note: not necessarily a Wrapper<T>

        if (this.equivalence.equals(that.equivalence)) {
          /*
           * We'll accept that as sufficient "proof" that either equivalence should be able to
           * handle either reference, so it's safe to circumvent compile-time type checking.

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

  }

  public static void assertEmpty(Iterable<?> iterable) {
    if (!isEmpty(iterable)) {
      fail("Not true that " + iterable + " is empty");
    }
  }

  public static void assertEmpty(Map<?, ?> map) {
    if (!map.isEmpty()) {
      fail("Not true that " + map + " is empty");
    }
  }

  public static void assertEqualInOrder(Iterable<?> expected, Iterable<?> actual) {

* For `PUT` requests to `/items/{item_id}`, read the body as JSON:
    * Check that it has a required attribute `name` that should be a `str`.
    * Check that it has a required attribute `price` that has to be a `float`.
    * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present.
    * All this would also work for deeply nested JSON objects.

message DaemonSetSpec {
  // A label query over pods that are managed by the daemon set.
  // Must match in order to be controlled.
  // If empty, defaulted to labels on Pod template.
  // More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.LabelSelector selector = 1;

  // An object that describes the pod that will be created.