private static final String MAVEN_PLUGIN_VALIDATION_KEY = "maven.plugin.validation";

    private static final String MAVEN_PLUGIN_VALIDATION_EXCLUDES_KEY = "maven.plugin.validation.excludes";

    private static final ValidationReportLevel DEFAULT_VALIDATION_LEVEL = ValidationReportLevel.INLINE;

    private static final Collection<ValidationReportLevel> INLINE_VALIDATION_LEVEL = Collections.unmodifiableCollection(

     * users to migrate their projects.
     */
    int VALIDATION_LEVEL_MAVEN_2_0 = 20;

    /**
     * Denotes validation as performed by Maven 3.0. This validation level is meant for existing projects.
     */
    int VALIDATION_LEVEL_MAVEN_3_0 = 30;

    /**

                projectPrefixValueSource =
                        new ProblemDetectingValueSource(projectPrefixValueSource, PREFIX_POM, PREFIX_PROJECT, problems);
            }

            prefixlessObjectBasedValueSource = new ObjectBasedValueSource(model);
            if (request.getValidationLevel() >= ModelBuilderRequest.VALIDATION_LEVEL_MAVEN_2_0) {

        request.projectBuild(true);
        request.session(InternalSession.from(session));
        request.source(ModelSource.fromPath(src));
        request.validationLevel(ModelBuilderRequest.VALIDATION_LEVEL_MINIMAL);
        request.locationTracking(false);
        request.modelResolver(modelResolver);
        request.transformerContextBuilder(modelBuilder.newTransformerContextBuilder());

        mavenSession.getRequest().setRootDirectory(pomFile.getParentFile().toPath());
        ProjectBuildingRequest configuration = new DefaultProjectBuildingRequest();
        configuration.setValidationLevel(ModelBuildingRequest.VALIDATION_LEVEL_MINIMAL);
        configuration.setRepositorySession(mavenSession.getRepositorySession());
        org.apache.maven.project.ProjectBuilder projectBuilder =

            }
        }
    }

    // ----------------------------------------------------------------------
    // Field validation
    // ----------------------------------------------------------------------

    /**
     * Asserts:
     * <p/>
     * <ul>
     * <li><code>string.length == null</code>

    private ProjectBuildingRequest toRequest(ProjectBuilderConfiguration configuration) {
        DefaultProjectBuildingRequest request = new DefaultProjectBuildingRequest();

        request.setValidationLevel(ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_2_0);
        request.setResolveDependencies(false);

        request.setLocalRepository(configuration.getLocalRepository());
        request.setBuildStartTime(configuration.getBuildStartTime());

                    configuration.setRemoteRepositories(repositoryRequest.getRemoteRepositories());
                    configuration.setValidationLevel(ModelBuildingRequest.VALIDATION_LEVEL_MINIMAL);
                    configuration.setProcessPlugins(false);
                    configuration.setRepositoryMerging(ProjectBuildingRequest.RepositoryMerging.REQUEST_DOMINANT);