### Question:
UpgradeCatalog251 extends AbstractUpgradeCatalog { @Override protected void executeDDLUpdates() throws AmbariException, SQLException { addBackgroundColumnToHostRoleCommand(); moveClusterHostColumnFromStageToRequest(); } @Inject  UpgradeCatalog251(Injector injector); @Override String getSourceVersion(); @Override String getTargetVersion();  }### Answer:
@Test public void testExecuteDDLUpdates() throws Exception { Capture<DBColumnInfo> hrcBackgroundColumnCapture = newCapture(); dbAccessor.addColumn(eq(UpgradeCatalog251.HOST_ROLE_COMMAND_TABLE), capture(hrcBackgroundColumnCapture)); expect(dbAccessor.getConnection()).andReturn(connection).anyTimes(); expect(connection.createStatement()).andReturn(statement).anyTimes(); expect(statement.executeQuery(anyObject(String.class))).andReturn(resultSet).anyTimes(); expect(configuration.getDatabaseType()).andReturn(Configuration.DatabaseType.POSTGRES).anyTimes(); replay(dbAccessor, configuration, connection, statement, resultSet); Module module = new Module() { @Override public void configure(Binder binder) { binder.bind(DBAccessor.class).toInstance(dbAccessor); binder.bind(OsFamily.class).toInstance(osFamily); binder.bind(EntityManager.class).toInstance(entityManager); binder.bind(Configuration.class).toInstance(configuration); } }; Injector injector = getInjector(createNiceMock(Clusters.class), createNiceMock(AmbariManagementControllerImpl.class)); UpgradeCatalog251 upgradeCatalog251 = injector.getInstance(UpgradeCatalog251.class); upgradeCatalog251.executeDDLUpdates(); verify(dbAccessor); DBColumnInfo captured = hrcBackgroundColumnCapture.getValue(); Assert.assertEquals(UpgradeCatalog251.HRC_IS_BACKGROUND_COLUMN, captured.getName()); Assert.assertEquals(Integer.valueOf(0), captured.getDefaultValue()); Assert.assertEquals(Short.class, captured.getType()); }