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;
  }

  /**

import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Collections.emptyList;
import static java.util.Collections.emptySet;
import static java.util.Collections.singleton;
import static java.util.Collections.singletonList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

   * Collections#emptyList}, and is preferable mainly for consistency and maintainability of your
   * code.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the list will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableList<E> of() {
    return (ImmutableList<E>) EMPTY;
  }

  /**

 * </blockquote>
 *
 * <p>When both endpoints exist, the upper endpoint may not be less than the lower. The endpoints
 * may be equal only if at least one of the bounds is closed:
 *
 * <ul>
 *   <li>{@code [a..a]} : a singleton range
 *   <li>{@code [a..a); (a..a]} : {@linkplain #isEmpty empty} ranges; also valid
 *   <li>{@code (a..a)} : <b>invalid</b>; an exception will be thrown
 * </ul>
 *
 * <h3>Warnings</h3>
 *
 * <ul>

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

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;

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

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;

import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Arrays.sort;
import static java.util.Collections.emptyList;
import static java.util.Collections.singleton;
import static java.util.Collections.sort;
import static java.util.Collections.unmodifiableList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Arrays.sort;
import static java.util.Collections.emptyList;
import static java.util.Collections.singleton;
import static java.util.Collections.sort;
import static java.util.Collections.unmodifiableList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

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

    private FileConfigDbm() {
    }

 * </blockquote>
 *
 * <p>When both endpoints exist, the upper endpoint may not be less than the lower. The endpoints
 * may be equal only if at least one of the bounds is closed:
 *
 * <ul>
 *   <li>{@code [a..a]} : a singleton range
 *   <li>{@code [a..a); (a..a]} : {@linkplain #isEmpty empty} ranges; also valid
 *   <li>{@code (a..a)} : <b>invalid</b>; an exception will be thrown
 * </ul>
 *
 * <h3>Warnings</h3>
 *
 * <ul>