import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Map;

/**
 * An implementation of {@link ImmutableTable} that holds a single cell.
 *
 * @author Gregory Kick
 */
@GwtCompatible
final class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
  final R singleRowKey;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Collections;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/** Implementation of an {@link Optional} containing a reference. */
@GwtCompatible
final class Present<T> extends Optional<T> {
  private final T reference;

  Present(T reference) {
    this.reference = reference;
  }

import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})
  int stackDepth;

  @Param({"-1", "3", "15"})
  int breakAt;

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link TestMapGenerator} for use with maps of strings.
 *
 * @author Chris Povirk
 * @author Jared Levy
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked

import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})
  int stackDepth;

  @Param({"-1", "3", "15"})
  int breakAt;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

/**
 * An {@link ImmutableAsList} implementation specialized for when the delegate collection is already
 * backed by an {@code ImmutableList} or array.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtIncompatible;
import org.jspecify.annotations.Nullable;

/**
 * A skeletal implementation of {@code RangeSet}.
 *
 * @author Louis Wasserman
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@GwtIncompatible

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * This class provides a skeletal implementation of the {@code Iterator} interface for sequences
 * whose next element can always be derived from the previous element. Null elements are not
 * supported, nor is the {@link #remove()} method.
 *
 * <p>Example:
 *

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.execution;

/**
 * Provides a skeleton implementation for execution listeners. The methods of this class are empty.
 *
 */
public class AbstractExecutionListener implements ExecutionListener {

    @Override
    public void projectDiscoveryStarted(ExecutionEvent event) {