### Question:
OsFamily { public Set<String> os_list(){ Set<String> r= new HashSet<>(); for ( String family : osMap.keySet()) { JsonOsFamilyEntry fam = osMap.get(family); for (String version: fam.getVersions()){ Set<String> data= new HashSet<>(); for (String item: fam.getDistro()) { data.add(item + version); } r.addAll(data); } } return r; } OsFamily(Configuration conf);  OsFamily(Properties properties); Set<String> findTypes(String os); String find(String os); String find_family(String os); Set<String> os_list(); boolean isUbuntuFamily(String osType); boolean isSuseFamily(String osType); boolean isRedhatFamily(String osType); boolean isOsInFamily(String osType, String osFamily); boolean isVersionedOsFamilyExtendedByVersionedFamily(String currentVersionedFamily, String versionedFamily); Map<String, String> getAliases();  }### Answer:
@Test public void testOSListing() throws Exception{ Set<String> actual_oslist = os_family.os_list(); Set<String> expected_oslist = new HashSet<>(Arrays.asList( "redhat6", "oraclelinux5", "suse11", "fedora6", "opensuse11", "centos6", "fedora5", "centos5", "ubuntu12", "redhat5", "sles11", "oraclelinux6", "debian12", "sled11", "win2012server6", "win2012serverr26", "win2008serverr26", "win2008server6" )); Assert.assertNotNull(actual_oslist); Assert.assertEquals(expected_oslist, actual_oslist); }