### Question:
DefaultInstallationService implements InstallationService, Initializable { public List<String> getDefaultJavaVersionInfo() throws InstallationException { try { Properties systemEnvVars = shellCommandHelper.getSystemEnvVars(); String javaHome = (String) systemEnvVars.get( "JAVA_HOME" ); if ( StringUtils.isEmpty( javaHome ) ) { return getJavaVersionInfo( System.getProperty( "java.home" ) ); } return getJavaVersionInfo( javaHome ); } catch ( Exception e ) { throw new InstallationException( e.getMessage(), e ); } }  void initialize(); Installation add( Installation installation ); Installation add( Installation installation, boolean automaticProfile ); void delete( Installation installation ); @SuppressWarnings( "unchecked" ) List<Installation> getAllInstallations(); Installation getInstallation( int installationId ); Installation getInstallation( String installationName ); void update( Installation installation ); ExecutorConfigurator getExecutorConfigurator( String type ); String getEnvVar( String type ); List<String> getDefaultJavaVersionInfo(); List<String> getJavaVersionInfo( Installation installation ); List<String> getExecutorVersionInfo( String path, ExecutorConfigurator executorConfigurator,
                                                Profile profile );  }### Answer:
@Test public void testGetDefaultJavaVersionInfo() throws Exception { InstallationService installationService = (InstallationService) lookup( InstallationService.ROLE, "default" ); List<String> infos = installationService.getDefaultJavaVersionInfo(); assertNotNull( infos ); }