DefaultExceptionHandler handler = new DefaultExceptionHandler();
        ExceptionSummary summary = handler.handleException(exception);

        String expectedReference = "http://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound";
        assertEquals(expectedReference, summary.getReference());
    }

    @Test
    void testHandleExceptionNoClassDefFoundErrorNull() {

    }

    public BuildSummary getBuildSummary(MavenProject project) {
        return buildSummaries.get(project);
    }

    public void addBuildSummary(BuildSummary summary) {
        buildSummaries.put(summary.getProject(), summary);
    }

    @Override
    public boolean canResume() {
        return canResume;
    }

    @Override
    public void setCanResume(boolean canResume) {

import org.apache.maven.project.MavenProject;

/**
 * Summarizes the result of a successful project build in the reactor.
 *
 */
public class BuildSuccess extends BuildSummary {

    /**
     * Creates a new build summary for the specified project.
     *
     * @param project The project being summarized, must not be {@code null}.
     * @param time The build time of the project in milliseconds.
     */

        NONE, // mute validation completely (validation issue collection still happens, it is just not reported!)
        INLINE, // inline, each "internal" problem one line next to mojo invocation
        SUMMARY, // at end, list of plugin GAVs along with ANY validation issues
        BRIEF, // each "internal" problem one line next to mojo invocation
        // and at end list of plugin GAVs along with "external" issues

    /**
     * Gets the build summary for the specified project.
     *
     * @param project The project to get the build summary for, must not be {@code null}.
     * @return The build summary for the project or {@code null} if the project has not been built (yet).
     */
    BuildSummary getBuildSummary(MavenProject project);

    /**
     * Add the specified build summary.
     *

 *
 */
public class BuildFailure extends BuildSummary {

    /**
     * The cause of the build failure.
     */
    private final Throwable cause;

    /**
     * Creates a new build summary for the specified project.
     *
     * @param project The project being summarized, must not be {@code null}.
     * @param time The build time of the project in milliseconds.

     */
    private final MavenProject project;

    /**
     * The build time of the project in milliseconds.
     */
    private final long time;

    /**
     * Creates a new build summary for the specified project.
     *
     * @param project The project being summarized, must not be {@code null}.
     * @param time The build time of the project in milliseconds.
     */