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

import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Stream;

import org.apache.maven.RepositoryUtils;

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

import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.function.UnaryOperator;
import java.util.stream.Collectors;

import org.apache.maven.RepositoryUtils;
import org.apache.maven.api.Service;
import org.apache.maven.api.Session;

        final MavenProject child = createMavenProject("maven-core-child");
        mavenProject.setCollectedProjects(Collections.singletonList(child));
        final List<MavenProject> listOfProjects = Collections.singletonList(mavenProject);

        final Set<MavenProject> requiredProjectsBySelectors =

        try {
            Map<String, ?> options = Collections.singletonMap(ToolchainsReader.IS_STRICT, Boolean.TRUE);

            try {
                toolchains = toolchainsReader.read(toolchainsSource.getInputStream(), options);
            } catch (ToolchainsParseException e) {
                options = Collections.singletonMap(ToolchainsReader.IS_STRICT, Boolean.FALSE);

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

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**

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

import java.util.Collection;
import java.util.Collections;

import org.apache.maven.api.ProducedArtifact;
import org.apache.maven.api.Service;
import org.apache.maven.api.Session;
import org.apache.maven.api.annotations.Experimental;

     */
    public static UpgradeResult empty() {
        return new UpgradeResult(Collections.emptySet(), Collections.emptySet(), Collections.emptySet());
    }

    /**
     * Merges this result with another result, combining the sets of POMs.
     * This allows proper aggregation of results from multiple strategies without double-counting.
     */
    public UpgradeResult merge(UpgradeResult other) {

    private MavenProject project;

    private List<MavenProject> topologicallySortedProjects = Collections.emptyList();

    private DependencyResolutionResult dependencyResolutionResult;

    private final List<Throwable> exceptions = new CopyOnWriteArrayList<>();

    private final Map<MavenProject, BuildSummary> buildSummaries = Collections.synchronizedMap(new IdentityHashMap<>());

    private boolean canResume = false;

 * under the License.
 */
package org.apache.maven.model.interpolation;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.TimeZone;

 */

package com.google.common.collect;

import java.util.Collections;
import java.util.Set;

/**
 * GWT emulation of {@link RegularImmutableSet}.
 *
 * @author Hayward Chan
 */
final class RegularImmutableSet<E> extends ForwardingImmutableSet<E> {
  static final RegularImmutableSet<Object> EMPTY =
      new RegularImmutableSet<Object>(Collections.emptySet());

  RegularImmutableSet(Set<E> delegate) {