throw new IllegalArgumentException(String.format("Multiple projects registered for path '%s'.", project.getPath()));
        }
        subProjects.put(project.getPath(), new HashSet<T>());
        addProjectToParentSubProjects(project);
    }

    public T removeProject(String path) {
        T project = projects.remove(path);
        assert project != null;
        subProjects.remove(path);