new ImmutableClassToInstanceMap<>(ImmutableMap.<Class<?>, Object>of());

  /**
   * Returns an empty {@code ImmutableClassToInstanceMap}.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   *
   * @since 19.0
   */
  @SuppressWarnings("unchecked")
  public static <B> ImmutableClassToInstanceMap<B> of() {
    return (ImmutableClassToInstanceMap<B>) EMPTY;
  }

  /**

    // ===================================================================================
    //                                                                           Singleton
    //                                                                           =========
    private static final FavoriteLogDbm _instance = new FavoriteLogDbm();

    private FavoriteLogDbm() {
    }

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.repository.metadata;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;
import javax.xml.stream.XMLStreamException;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.testing.Helpers.copyToSet;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static java.util.Collections.singleton;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Multimap;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        StandardCrawlerContainer container = new StandardCrawlerContainer().singleton("mimeTypeHelper", MimeTypeHelperImpl.class)//
                .singleton("ftpClient", FtpClient.class);
        ftpClient = container.getComponent("ftpClient");
    }

    public RobotsTxtHelper robotsTxtHelper;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        StandardCrawlerContainer container = new StandardCrawlerContainer().singleton("robotsTxtHelper", RobotsTxtHelper.class);
        robotsTxtHelper = container.getComponent("robotsTxtHelper");
    }

    public void testParse() {
        RobotsTxt robotsTxt;

    // ===================================================================================
    //                                                                           Singleton
    //                                                                           =========
    private static final GroupDbm _instance = new GroupDbm();

    private GroupDbm() {
    }

        }
      }

      Control control = new Control();
      Hasher controlSink = control.newHasher(1024);

      Iterable<Hasher> sinksAndControl =
          Iterables.concat(sinks, Collections.singleton(controlSink));
      for (int insertion = 0; insertion < totalInsertions; insertion++) {
        RandomHasherAction.pickAtRandom(random).performAction(random, sinksAndControl);
      }

    // ===================================================================================
    //                                                                           Singleton
    //                                                                           =========
    private static final WebAuthenticationDbm _instance = new WebAuthenticationDbm();

    private WebAuthenticationDbm() {
    }

  }

  public void testOrNull_absent() {
    assertNull(Optional.absent().orNull());
  }

  public void testAsSet_present() {
    Set<String> expected = Collections.singleton("a");
    assertEquals(expected, Optional.of("a").asSet());
  }

  public void testAsSet_absent() {
    assertTrue("Returned set should be empty", Optional.absent().asSet().isEmpty());
  }