code: private SimpleDirectedGraph<ModuleModel, Edge> buildModuleDependencyGraph() {
  		SimpleDirectedGraph<ModuleModel, Edge> g = buildExportGraph();
  
  		// add import dependencies
  		for (ModuleModel module : modules.values()) {
  			for (ModuleModel imported : module.importedModules) {
  				g.addEdge(module, imported);
  			}
  		}
  		return g;
  	}
docs: Build a graph containing all module dependencies