* Gets the identifiers of those profiles that should be activated by explicit demand.
     *
     * @return The identifiers of those profiles to activate, never {@code null}.
     */
    List<String> getActiveProfileIds();

    /**
     * Gets the identifiers of those profiles that should be deactivated by explicit demand.
     *
     * @return The identifiers of those profiles to deactivate, never {@code null}.
     */

import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;

import static java.util.stream.Collectors.toSet;

/**
 * Container for storing the request from the user to activate or de-activate certain profiles and optionally fail the
 * build if those profiles do not exist.
 */
public class ProfileActivation {
    private final Map<String, ActivationSettings> activations = new HashMap<>();

    /**

        if (name == null || name.isEmpty()) {
            problems.add(
                    BuilderProblem.Severity.ERROR,
                    ModelProblem.Version.BASE,
                    "The property name is required to activate the profile " + profile.getId(),
                    property.getLocation(""));
            return false;
        }

        String sysValue = context.getUserProperties().get(name);
        if (sysValue == null) {

    </profile>
    <profile>
      <id>file</id>
      <activation>
        <file>
          <exists>simple.xml</exists>
        </file>
      </activation>
      <properties>
        <profile.file>activated</profile.file>
      </properties>
    </profile>
  </profiles>

  <artifactId>test</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>Maven Integration Test :: it0021</name>
  <description>
    Test pom-level profile inclusion (this one is activated by system property).
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>
        <artifactId>maven-it-plugin-dependency-resolution</artifactId>

     *            {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     * @return The profiles that have been activated, never {@code null}.
     */
    List<Profile> getActiveProfiles(
            Collection<Profile> profiles, ProfileActivationContext context, ModelProblemCollector problems);

     *
     * @return the file model, never {@code null}.
     */
    @Nonnull
    Model getFileModel();

    /**
     * Returns the file model + profile injection.
     *
     * @return the activated file model, never {@code null}.
     */
    @Nonnull
    Model getActivatedFileModel();

    /**
     * Gets the file model + build pom transformation, without inheritance nor interpolation.
     *

     */
    public void explicitlyActivate(String profileId) {
        if (!activatedIds.contains(profileId)) {
            logger.debug("Profile with id: '" + profileId + "' has been explicitly activated.");

            activatedIds.add(profileId);
        }
    }

    /* (non-Javadoc)
     * @see org.apache.maven.profiles.ProfileManager#explicitlyActivate(java.util.List)
     */

import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static java.util.stream.Collectors.toSet;

/**
 * Container for storing the request from the user to activate or deactivate certain projects and optionally fail the
 * build if those projects do not exist.
 */
public class ProjectActivation {
    private static class ProjectActivationSettings {
        /**

            boolean reverseName = false;

            if (name == null) {
                throw new ProfileActivationException(
                        "The property name is required to activate the profile '" + profile.getId() + "'");
            }

            if (name.startsWith("!")) {
                reverseName = true;
                name = name.substring(1);
            }