*/
  public static Escaper xmlContentEscaper() {
    return XML_CONTENT_ESCAPER;
  }

  /**
   * Returns an {@link Escaper} instance that escapes special characters in a string so it can
   * safely be included in XML document as an attribute value. See section <a
   * href="http://www.w3.org/TR/2008/REC-xml-20081126/#AVNormalize">3.3.3</a> of the XML
   * specification.
   *

    Escaper escaper = Escapers.builder().setSafeRange('a', 'z').build();
    assertThat(escaper.escape("The Quick Brown Fox")).isEqualTo("The Quick Brown Fox");
  }

  public void testBuilderInitialStateNoneUnsafe() {
    // No characters are unsafe by default (safeMin == 0, safeMax == 0xFFFF).
    Escaper escaper = Escapers.builder().setUnsafeReplacement("X").build();

      "\0abyz\u0080\u0100\u0800\u1000ABYZ\uffff" + SMALLEST_SURROGATE + "0189" + LARGEST_SURROGATE;

  // Escapes nothing
  private static final UnicodeEscaper NOP_ESCAPER =
      new UnicodeEscaper() {
        @Override
        protected char @Nullable [] escape(int c) {
          return null;
        }
      };

  // Escapes everything except [a-zA-Z0-9]
  private static final UnicodeEscaper SIMPLE_ESCAPER =

      "\0abyz\u0080\u0100\u0800\u1000ABYZ\uffff" + SMALLEST_SURROGATE + "0189" + LARGEST_SURROGATE;

  // Escapes nothing
  private static final UnicodeEscaper NOP_ESCAPER =
      new UnicodeEscaper() {
        @Override
        protected char @Nullable [] escape(int c) {
          return null;
        }
      };

  // Escapes everything except [a-zA-Z0-9]
  private static final UnicodeEscaper SIMPLE_ESCAPER =

/**
 * Tests for {@link PercentEscaper}.
 *
 * @author David Beaumont
 */
@GwtCompatible
@NullUnmarked
public class PercentEscaperTest extends TestCase {

  /** Tests that the simple escaper treats 0-9, a-z and A-Z as safe */
  public void testSimpleEscaper() {
    UnicodeEscaper e = new PercentEscaper("", false);
    for (char c = 0; c < 128; c++) {

/**
 * Tests for {@link PercentEscaper}.
 *
 * @author David Beaumont
 */
@GwtCompatible
@NullUnmarked
public class PercentEscaperTest extends TestCase {

  /** Tests that the simple escaper treats 0-9, a-z and A-Z as safe */
  public void testSimpleEscaper() {
    UnicodeEscaper e = new PercentEscaper("", false);
    for (char c = 0; c < 128; c++) {

        if (value.split("\\s").length > 1) {
            return new StringBuilder().append('"').append(value.replace('"', ' ')).append('"').toString();
        }
        return value;
    }

    /**
     * Escapes special characters in a query string if escaping is enabled.
     * Replaces reserved characters with their escaped equivalents based on the Constants.RESERVED array.
     *
     * @param value the query string to escape

/**
 * JSON utilities.
 *
 * @author shinsuke
 *
 */
public class JsonUtil {

    /**
     * Defualt constructor.
     */
    protected JsonUtil() {
    }

    /**
     * Escapes a value as Json string.
     *
     * @param value input
     * @return escaped string.
     */
    public static String escape(final String value) {
        if (value == null) {
            return null;
        }

    }

    /**
     * Escapes a callback name.
     * @param callbackName The callback name.
     * @return The escaped callback name.
     */
    protected String escapeCallbackName(final String callbackName) {
        return "/**/" + callbackName.replaceAll("[^0-9a-zA-Z_\\$\\.]", StringUtil.EMPTY);
    }

    /**
     * Escapes a JSON object.
     * @param obj The object to escape.

        }
        if (keyObj instanceof final Number key) {
            return OptionalThing.of(key.toString());
        }
        return OptionalThing.empty();
    }

    /**
     * Escapes special characters in a value string for safe logging.
     *
     * @param action the string value to escape
     * @return the escaped string with tabs replaced by spaces
     */