*
     * @param model
     * @param problems
     */
    public static <T> Result<T> error(T model, Iterable<? extends ModelProblem> problems) {
        return new Result<>(true, model, problems);
    }

    /**
     * New result - determine whether error or success by checking problems for errors
     *
     * @param model
     * @param problems
     */

        if (p1 == p2) {
            return true;
        }
        // update policy doesn't affect contents
        return p1.isEnabled() == p2.isEnabled() && Objects.equals(p1.getChecksumPolicy(), p2.getChecksumPolicy());
    }

    private static boolean repositoryEquals(RemoteRepository r1, RemoteRepository r2) {
        if (r1 == r2) {
            return true;
        }

     *
     * @return {@code true} if the project is the top level project for this build
     */
    boolean isTopProject();

    /**
     * Returns a boolean indicating if the project is a root project,
     * meaning that the {@link #getRootDirectory()} and {@link #getBasedir()}
     * points to the same directory, and that either {@link Model#isRoot()}

  <description>
    Configuration of custom lifecycle mappings for the plugin, as generally stored in
    {@code META-INF/maven/lifecycle.xml} in a plugin's jar artifact.
  </description>
  <classes>
    <class rootElement="true" xml.tagName="lifecycles" xsd.compositor="sequence">
      <name>LifecycleConfiguration</name>
      <version>1.0.0</version>
      <description>Root element of the {@code lifecycle.xml} file.</description>
      <fields>

 * or a {@code pom.xml} containing the {@code root="true"} attribute.
 */
public interface RootLocator {

    String UNABLE_TO_FIND_ROOT_PROJECT_MESSAGE = "Unable to find the root directory. "
            + "Create a .mvn directory in the root directory or add the root=\"true\""
            + " attribute on the root project's model to identify it.";

    @Nonnull

        <filtering>true</filtering>
      </resource>
    </resources>
    <testResources>
      <testResource>
        <directory>${project.basedir}/src/test/resources</directory>
      </testResource>
      <testResource>
        <directory>${project.basedir}/src/test/resources-filtered</directory>
        <filtering>true</filtering>
      </testResource>
    </testResources>
  </build>

     */
    private static boolean validateStringEmpty(
            List<BuilderProblem> problems, String fieldName, String string, String message) {
        if (string == null || string.length() == 0) {
            return true;
        }

        addViolation(problems, BuilderProblem.Severity.WARNING, fieldName, null, message);

        return false;
    }

    /**
     * Asserts:
     * <p/>
     * <ul>

              </templates>
              <params>
                <param>packageModelV4=org.apache.maven.api.toolchain</param>
                <param>locationTracking=true</param>
                <param>generateLocationClasses=true</param>
              </params>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

        // v1-->v2
        graph.addEdge(v1, v2, new MetadataGraphEdge("1.1", true, null, null, 2, 1));
        graph.addEdge(v1, v2, new MetadataGraphEdge("1.2", true, null, null, 2, 2));

        // v1-->v3
        graph.addEdge(v1, v3, new MetadataGraphEdge("1.1", true, null, null, 2, 1));
        graph.addEdge(v1, v3, new MetadataGraphEdge("1.2", true, null, null, 4, 2));

        // v3-->v4

        MavenExecutionRequest request = new DefaultMavenExecutionRequest()
                .setPom(pom)
                .setProjectPresent(true)
                .setShowErrors(true)
                .setPluginGroups(Arrays.asList("org.apache.maven.plugins"))
                .setLocalRepository(getLocalRepository())
                .setRemoteRepositories(getRemoteRepositories())