### Question:
InformationManager { public String getPageList() { InformationPage[] pages1 = new InformationPage[this.pages.size()]; int counter = 0; for ( InformationPage p : this.pages.values() ) { pages1[counter] = p; counter++; } Arrays.sort( pages1, Comparator.comparing( InformationPage::getName ) ); Gson gson = new Gson(); return gson.toJson( pages1, InformationPage[].class ); } private  InformationManager( final String instanceId ); static InformationManager getInstance(); static InformationManager getInstance( final String instanceId ); static void close( final String id ); void addPage( final InformationPage page ); void removePage( final InformationPage page ); void addGroup( final InformationGroup... groups ); void removeGroup( final InformationGroup... groups ); void registerInformation( final Information... infos ); void removeInformation( final Information... infos ); Information getInformation( final String key ); String getPageList(); InformationPage getPage( final String id ); InformationGroup getGroup( final String id ); InformationManager observe( final InformationObserver observer ); void notify( final Information i );  }### Answer:
@Test public void getPageList() { System.out.println( this.im.getPageList() ); }