MavenProject project = (MavenProject) project2;
String id = ArtifactUtils.versionlessKey(project.getGroupId(), project.getArtifactId());
if (dag.getVertex(id) != null) {
throw new DuplicateProjectException("Project '" + id + "' is duplicated in the reactor");
}
dag.addVertex(id);
projectMap.put(id, project);