* @param currentUrl the current URL
     * @param baseHref the base href value from HTML
     * @return the base URL
     * @throws MalformedURLException if the URL is malformed
     */
    protected URL getBaseUrl(final String currentUrl, final String baseHref) throws MalformedURLException {
        if (baseHref != null) {
            return getURL(currentUrl, baseHref);
        }
        return new URL(currentUrl);

import java.io.File;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.HashSet;
import java.util.Set;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**

import com.google.common.testing.NullPointerTester;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.jar.Attributes;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;

import com.google.common.testing.NullPointerTester;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.file.Path;
import java.util.jar.Attributes;
import java.util.jar.JarOutputStream;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;

        try {
            transformer.getURL("not-a-url", "/page");
            fail();
        } catch (final Exception e) {
            // MalformedURLException expected for invalid base URL
        }
    }

    @Test
    public void test_normalizeCanonicalUrl_withMalformedRelative() throws Exception {