- Some base services that are available to code hosted by the runtime. This varies by runtime.
- Additional constraints. For example, the CLI client runtimes limit the libraries that are available to the code in that runtime, for performance reasons. 

Other modules and platforms define the services that they contribute to the runtime.

 *   <dd>An extension of {@link java.util.Collection} that may contain duplicate values like a
 *       {@link java.util.List}, yet has order-independent equality like a {@link java.util.Set}.
 *       One typical use for a multiset is to represent a histogram.
 *   <dt>{@link ClassToInstanceMap}
 *   <dd>An extension of {@link java.util.Map} that associates a raw type with an instance of that
 *       type.
 * </dl>
 *
 * <h2>Ranges</h2>
 *

enum class Protocol(
  private val protocol: String,
) {
  /**
   * An obsolete plaintext framing that does not use persistent sockets by default.
   */
  HTTP_1_0("http/1.0"),

  /**
   * A plaintext framing that includes persistent connections.
   *
   * This version of OkHttp implements [RFC 7230][rfc_7230], and tracks revisions to that spec.
   *
   * [rfc_7230]: https://tools.ietf.org/html/rfc7230
   */
  HTTP_1_1("http/1.1"),

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder` { #using-the-jsonable-encoder }

Let's imagine that you have a database `fake_db` that only receives JSON compatible data.

For example, it doesn't receive `datetime` objects, as those are not compatible with JSON.

# Response - Change Status Code { #response-change-status-code }

You probably read before that you can set a default [Response Status Code](../tutorial/response-status-code.md).

But in some cases you need to return a different status code than the default.

## Use case { #use-case }

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

  }

  /**
   * Returns the {@link EventBus} that handled the event and the subscriber. Useful for broadcasting
   * a new event based on the error.
   */
  public EventBus getEventBus() {
    return eventBus;
  }

  /** Returns the event object that caused the subscriber to throw. */
  public Object getEvent() {
    return event;
  }

  /** Returns the object context that the subscriber was called on. */

      if (object instanceof AsList) {
        AsList that = (AsList) object;
        return this.parent.equals(that.parent);
      }
      // We could delegate to super now but it would still box too much
      if (!(object instanceof List)) {
        return false;
      }
      List<?> that = (List<?>) object;
      if (this.size() != that.size()) {
        return false;
      }
      int i = parent.start;

      if (object instanceof AsList) {
        AsList that = (AsList) object;
        return this.parent.equals(that.parent);
      }
      // We could delegate to super now but it would still box too much
      if (!(object instanceof List)) {
        return false;
      }
      List<?> that = (List<?>) object;
      if (this.size() != that.size()) {
        return false;
      }
      int i = parent.start;

    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

  @Test
  public void addEdge_parallelSelfLoopEdge_notAllowed() {
    assume().that(graphIsMutable()).isTrue();
    assume().that(network.allowsSelfLoops()).isTrue();
    assume().that(network.allowsParallelEdges()).isFalse();

    addEdge(N1, N1, E11);
    IllegalArgumentException e =
        assertThrows(