import org.codelibs.core.exception.IORuntimeException;
import org.codelibs.core.exception.SAXRuntimeException;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;

/**
 * Utility class for {@link DocumentBuilder}.
 *
 * @author higa
 */
public abstract class DocumentBuilderUtil {

    /**
     * Do not instantiate.
     */
    protected DocumentBuilderUtil() {
    }

        if (context == null) {
            return null;
        }
        return context.get(key);
    }

    /**
     * Sets the project's class realm. <strong>Warning:</strong> This is an internal utility method that is only public
     * for technical reasons, it is not part of the public API. In particular, this method can be changed or deleted
     * without prior notice and must not be used by plugins.
     *

     */
    public static final int DEFAULT_MAX_READ_WRITE_SIZE = 1048576; // 1MB

    /**
     * Private constructor to prevent instantiation
     */
    private RdmaCapabilities() {
        // Utility class
    }

 */
package org.codelibs.core.convert;

import static org.codelibs.core.misc.AssertionUtil.assertArgumentNotNull;

import java.util.Calendar;
import java.util.Locale;
import java.util.TimeZone;

/**
 * Utility class for conversions related to {@link Calendar}.
 *
 * @author higa
 */
public abstract class CalendarConversionUtil {

    /**
     * Do not instantiate.
     */
    protected CalendarConversionUtil() {

 * used in DCE/RPC communications.
 */
public class rpc {

    /**
     * Private constructor to prevent instantiation of utility class.
     */
    private rpc() {
        // Utility class
    }

    /**
     * UUID (Universally Unique Identifier) structure for DCE/RPC.
     * Represents a 128-bit UUID as defined by DCE/RPC specification.
     */

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Utility methods and classes for networking (such as IP addresses and domain names).
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 *
 * @author Craig Berry
 */

import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

/**
 * Utility class for creating test fixtures and reducing code duplication in tests.
 */
public final class TestUtils {

    private TestUtils() {
        // Utility class
    }

    /**
     * Creates a mock UpgradeContext with default settings.
     *
     * @return a mock UpgradeContext

Es una especificación bastante extensa y cubre varios casos de uso complejos.

Incluye formas de autenticarse usando un "tercero".

Eso es lo que todos los sistemas con "iniciar sesión con Facebook, Google, X (Twitter), GitHub" utilizan internamente.

### OAuth 1 { #oauth-1 }

Hubo un OAuth 1, que es muy diferente de OAuth2, y más complejo, ya que incluía especificaciones directas sobre cómo encriptar la comunicación.

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;

import org.codelibs.core.misc.LocaleUtil;

/**
 * Utility class for {@link DecimalFormat}.
 *
 * @author higa
 */
public abstract class DecimalFormatUtil {

    /**
     * Do not instantiate.
     */
    protected DecimalFormatUtil() {
    }

    /**

import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A utility similar to {@link IteratorTester} for testing a {@link ListIterator} against a known
 * good reference implementation. As with {@code IteratorTester}, a concrete subclass must provide