You can override these exception handlers with your own.

### Override request validation exceptions { #override-request-validation-exceptions }

When a request contains invalid data, **FastAPI** internally raises a `RequestValidationError`.

And it also includes a default exception handler for it.

                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

/// tip

If you have strict type checks in your editor, mypy, etc, you can declare the function return type as `Any`.

That way you tell the editor that you are intentionally returning anything. But FastAPI will still do the data documentation, validation, filtering, etc. with the `response_model`.

///

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.dict.protwords;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

/**
 * Form class for editing protected words dictionary entries in the admin interface.

import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.lastaflute.web.util.LaRequestUtil;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * The list form for Search List.
 */
public class ListForm extends SearchRequestParams {

    /**
     * Default constructor.
     */

    }

    return NO_SUFFIX_FOUND;
  }

  /**
   * Returns an instance of {@link InternetDomainName} after lenient validation. Specifically,
   * validation against <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>
   * ("Internationalizing Domain Names in Applications") is skipped, while validation against <a
   * href="http://www.ietf.org/rfc/rfc1035.txt">RFC 1035</a> is relaxed in the following ways:
   *
   * <ul>

                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

     * undergone any updates by the model builder, e.g. reflects neither inheritance nor interpolation.
     *
     * @return The raw model, never {@code null}.
     */
    Model getRawModel();

    /**
     * Gets the specified raw model as it was read from a model source. Apart from basic validation, a raw model has not

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.general;

import org.lastaflute.web.validation.Required;

import jakarta.validation.constraints.Size;

/**
 * The mail form for General settings.
 */
public class MailForm {

    /**
     * Default constructor.
     */
    public MailForm() {

        final byte[] testData = "test data for validation".getBytes();
        final ByteArrayInputStream in = new ByteArrayInputStream(testData);
        final int availableBefore = in.available();

        extractor.testValidateInputStream(in);

        final int availableAfter = in.available();
        assertEquals("Stream should not be consumed by validation", availableBefore, availableAfter);
    }

    /**