public void register(final Class<? extends FeatureInstaller> installer, final Class extension) {
        Preconditions.checkArgument(installerTypes.contains(installer), "Installer %s not registered",
                installer.getSimpleName());
        if (!extensions.containsKey(installer)) {
            extensions.put(installer, Lists.<Class<?>>newArrayList());
        }
        extensions.get(installer).add(extension);
    }
public void register ( final Class < ? extends FeatureInstaller > installer , final Class extension ) { Preconditions . checkArgument ( installerTypes . contains ( installer ) , "Installer %s not registered" , installer . getSimpleName ( ) ) ; if ( ! extensions . containsKey ( installer ) ) { extensions . put ( installer , Lists . < Class < ? > > newArrayList ( ) ) ; } extensions . get ( installer ) . add ( extension ) ; }
@param installer installer type
@param extension feature type to store