# Additional Responses in OpenAPI { #additional-responses-in-openapi }

/// warning

This is a rather advanced topic.

If you are starting with **FastAPI**, you might not need this.

///

You can declare additional responses, with additional status codes, media types, descriptions, etc.

Those additional responses will be included in the OpenAPI schema, so they will also appear in the API docs.

 * the specific service interface being implemented.
 * <p>
 * All SPI services should be annotated with {@link Consumer} to indicate they are meant to be
 * implemented by plugins and extensions rather than used by them.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer

    public static final String CHILDREN_COMBINATION_APPEND = "append";
    /**
     * Default mode for combining children DOMs during merge.
     * When element names match, the process will try to merge the element data,
     * rather than putting the dominant and recessive elements as siblings.
     */
    public static final String DEFAULT_CHILDREN_COMBINATION_MODE = CHILDREN_COMBINATION_MERGE;

  }

  /**
   * Creates a suite whose map has some elements filtered out of view.
   *
   * <p>Because the map may be ascending or descending, this test must derive the relative order of
   * these extreme values rather than relying on their regular sort ordering.
   */
  final TestSuite createSubmapSuite(
      FeatureSpecificTestSuiteBuilder<
              ?, ? extends OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>>>

        assertTrue(primaryScore > baseScore);

        // High error rate should reduce score
        channelInfo.setState(ChannelState.ESTABLISHED);
        channelInfo.setPrimary(false);
        for (int i = 0; i < 20; i++) {
            channelInfo.incrementRequestsSent();
            channelInfo.incrementErrors(); // 100% error rate
        }
        int highErrorScore = channelInfo.getScore();

### Network

    /**
     * Appends a quoted-string to a StringBuilder.
     *
     * RFC 2388 is rather vague about how one should escape special characters in form-data
     * parameters, and as it turns out Firefox and Chrome actually do rather different things, and
     * both say in their comments that they're not really sure what the right approach is. We go

   *
   * <p>This method is useful primarily when we make a reflective call to a method with no {@code
   * throws} clause: Java forces us to handle an arbitrary {@link Throwable} from that method,
   * rather than just the {@link RuntimeException} or {@link Error} that should be possible. (And in
   * fact the static type of {@link Throwable} is occasionally justified even for a method with no

   *
   * <p>This method is useful primarily when we make a reflective call to a method with no {@code
   * throws} clause: Java forces us to handle an arbitrary {@link Throwable} from that method,
   * rather than just the {@link RuntimeException} or {@link Error} that should be possible. (And in
   * fact the static type of {@link Throwable} is occasionally justified even for a method with no

    /**
     * Prefix used to identify regex patterns in related content terms.
     * When a term starts with this prefix, it is treated as a regular expression
     * pattern rather than an exact match term.
     */
    protected String regexPrefix = "regex:";

    /**
     * Placeholder string used in regex-based related content templates.