How to list module dependencies?

I'm trying to attach a project library to a module if it's not yet attached. Like this:

```

for (Module module : ModuleManager.getInstance(project).getModules()) {
    final ModifiableRootModel modifiableModel = modelsProvider.getModuleModifiableModel(module);
    Library libraryByName = modifiableModel.getModuleLibraryTable().getLibraryByName(libraryName);

    if (libraryByName != null) // this unfortunately never happens :-(
        continue;

    modifiableModel.addLibraryEntry(library);
    modelsProvider.commitModuleModifiableModel(modifiableModel);
}
```

However ` modifiableModel.getModuleLibraryTable().getLibraryByName(libraryName)` always returns `null`, and also `modifiableModel.getModuleLibraryTable().getLibraries()` is always just returning an empty array. 

But actually the library is already attached after the loop was run once and I end up having multiple copies of my libraries attached to each module:

Is there a more correct way to list attached module dependencies?