**FastAPI** uses it so that, if you use a Pydantic model in `response_model`, and your data has an error, you will see the error in your log.

But the client/user will not see it. Instead, the client will receive an "Internal Server Error" with an HTTP status code `500`.

            lsarpc.LsarTransNameArray names = new lsarpc.LsarTransNameArray();
            names.count = in.length;
            names.names = new lsarpc.LsarTranslatedName[in.length];
            // First is a user
            names.names[0] = new lsarpc.LsarTranslatedName();
            names.names[0].sid_type = (short) jcifs.SID.SID_TYPE_USER;
            names.names[0].name = new UnicodeString("alice", false);

                        final String userCode = userInfoHelper.getUserCode();

                        if (StringUtil.isBlank(userCode)) {
                            throw new WebApiException(HttpServletResponse.SC_BAD_REQUEST, "No user session.");
                        }
                        if (StringUtil.isBlank(favoriteUrl)) {
                            throw new WebApiException(HttpServletResponse.SC_BAD_REQUEST, "URL is null.");

 * your own escapers extend this class and implement the {@link #escape(char)} method.
 *
 * @author Sven Mawson
 * @since 15.0
 */
@GwtCompatible
@SuppressWarnings("EscapedEntity") // We do mean for the user to see "<" etc.
public abstract class CharEscaper extends Escaper {
  /** Constructor for use by subclasses. */
  protected CharEscaper() {}

  /**
   * Returns the escaped form of a given literal string.
   *

    public String id;

    /** Search term for filtering related content. */
    public String term;

    /** Content text for filtering related content. */
    public String content;

    /** User who created the related content. */
    public String createdBy;

    /** Creation time of the related content. */
    public String createdTime;

    /** Version number for optimistic locking. */

import org.codelibs.fess.app.web.CrudMode;
import org.codelibs.fess.app.web.api.ApiResult;
import org.codelibs.fess.app.web.api.admin.FessApiAdminAction;
import org.codelibs.fess.opensearch.user.exentity.Role;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.JsonResponse;

import jakarta.annotation.Resource;

/**
 * API action for admin role management.
 */

            tempDir.delete();
            tempDir.mkdirs();

            // robots.txt
            StringBuilder buf = new StringBuilder();
            buf.append("User-agent: *").append('\n');
            buf.append("Disallow: /admin/").append('\n');
            buf.append("Disallow: /websvn/").append('\n');
            final File robotTxtFile = new File(tempDir, "robots.txt");

								<div class="dropdown">
									<a id="userMenu" class="nav-link dropdown-toggle" data-bs-toggle="dropdown"
										href="#" role="button" aria-haspopup="true"
										aria-expanded="false"> <em class="fa fa-fw fa-user">
										<span>${username}</span>
									</a>
									<div class="dropdown-menu" aria-labelledby="userMenu">
										<c:if test="${editableUser == true}">

								<div class="dropdown">
									<a id="userMenu" class="nav-link dropdown-toggle" data-bs-toggle="dropdown"
										href="#" role="button" aria-haspopup="true"
										aria-expanded="false"> <em class="fa fa-fw fa-user">
										<span>${username}</span>
									</a>
									<div class="dropdown-menu" aria-labelledby="userMenu">
										<c:if test="${editableUser == true}">

import okhttp3.UrlComponentEncodingTester.Component

fun urlComponentEncodingTesterJvmPlatform(component: Component): UrlComponentEncodingTester.Platform =
  when (component) {
    Component.USER ->
      UrlComponentEncodingTesterJvmPlatform()
        .escapeForUri('%'.code)

    Component.PASSWORD ->
      UrlComponentEncodingTesterJvmPlatform()
        .escapeForUri('%'.code)

    Component.HOST ->