There are a few other methods which are potentially of interest within the Module interface. Firstly the Module provides access to the ModuleContext class, which contains the public Module getModule(ModuleIdentifier ident). This enables access to any other Modules in the system, beyond those named as required modules. As they are not required they may be unavailable, so checking the public boolean isModuleAvailable(ModuleIdentifier identifier) first is probably wise.
And finally the ModuleContext class gives access to the public Object getConfig() method. Of itself this is not that useful. Its used internally to provide XML configuration though, which is described in Section 5.2.