code: @Test public void testEnableDisableAddColumnDeleteColumn() throws Exception {
    byte[] tableName=Bytes.toBytes("testMasterAdmin");
    TEST_UTIL.createTable(tableName,HConstants.CATALOG_FAMILY);
    this.admin.disableTable(tableName);
    try {
      new HTable(TEST_UTIL.getConfiguration(),tableName);
    }
   catch (  org.apache.hadoop.hbase.client.RegionOfflineException e) {
    }
    this.admin.addColumn(tableName,new HColumnDescriptor("col2"));
    this.admin.enableTable(tableName);
    try {
      this.admin.deleteColumn(tableName,Bytes.toBytes("col2"));
    }
   catch (  TableNotDisabledException e) {
    }
    this.admin.disableTable(tableName);
    this.admin.deleteColumn(tableName,Bytes.toBytes("col2"));
    this.admin.deleteTable(tableName);
  }
  