}

    /**
     * Mark a profile as required and activated.
     * @param id The identifier of the profile.
     */
    public void activateRequiredProfile(String id) {
        this.activations.put(id, ActivationSettings.ACTIVATION_REQUIRED);
    }

    /**
     * Mark a profile as optional and activated.
     * @param id The identifier of the profile.
     */

      <description><![CDATA[
        This is an activator which will detect an operating system's attributes in order to activate
        its profile.
      ]]></description>
      <fields>
        <field>
          <name>name</name>
          <version>1.0.0</version>
          <type>String</type>
          <description>The name of the OS to be used to activate a profile</description>
        </field>
        <field>

        }
    }

    /**
     * List of activated and deactivated projects.
     */
    private final List<ProjectActivationSettings> activations = new ArrayList<>();

    /**
     * Adds a project activation to the request.
     * @param selector The selector of the project.
     * @param active Should the project be activated?
     * @param optional Can the build continue if the project does not exist?

                <property>
                    <name>myproperty</name>
                    <value>test</value>
                </property>
            </activation>
            <properties>
                <profile.file>activated-1</profile.file>
            </properties>
        </profile>
        <profile>
            <id>another-two-conditions</id>
            <activation>
                <property>

   |
   | As noted above, profiles can be activated in a variety of ways. One way - the activeProfiles
   | section of this document (settings.xml) - will be discussed later. Another way essentially
   | relies on the detection of a property, either matching a particular value for the property,
   | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a

      <description>
        This is an activator which will detect an operating system's attributes in order to activate
        its profile.
      </description>
      <fields>
        <field>
          <name>name</name>
          <version>1.0.0+</version>
          <type>String</type>
          <description>
            The name of the OS to be used to activate a profile.
          </description>
        </field>

     *            {@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);

    /**

    /**
     * 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.
     *

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

            // Use SLF4J formatter for consistency with warnings reported by logger
            final String message = MessageFormatter.format(
                            "The requested profiles {} could not be activated or deactivated because they do not"
                                    + " exist.",
                            notFoundRequiredProfiles)
                    .getMessage();