UUID ver1 = m1.getVersion();
assert DatabaseDescriptor.getDefsVersion().equals(ver1);
// rename it.
Migration m2 = new RenameColumnFamily("Keyspace1", "MigrationCf_1", "MigrationCf_2");
m2.apply();
UUID ver2 = m2.getVersion();
assert DatabaseDescriptor.getDefsVersion().equals(ver2);
// drop it.
Migration m3 = new DropColumnFamily("Keyspace1", "MigrationCf_2");