code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  //
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  package com.google.checkstyle.test.chapter4formatting.rule461verticalwhitespace; //warn
  import java.io.Serializable; //warn
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.Callable;
  import java.util.Collections;
  import java.util.Calendar;
  import java.util.Set;
  
  import javax.swing.AbstractAction;
  
  import org.apache.commons.beanutils.locale.converters.ByteLocaleConverter;
  class InputEmptyLineSeparator //warn
  {
      public static final double FOO_PI = 3.1415;
      private boolean flag = true;
      static {  //warn
          //empty static initializer
      }
  
      {
          //empty instance initializer
      }
  
      /**
       *
       *
       *
       */
      private InputEmptyLineSeparator()
      {
          //empty
      }
  
      public int compareTo(InputEmptyLineSeparator aObject)
      {
          int number = 0;
          return 0;
      }
      /**
       *
       * @param task
       * @param result
       * @return
       */
      public static <T> Callable<T> callable(Runnable task, T result) // warn
      {
          return null;
      }
  
      public int getBeastNumber()
      {
          return 666;
      }
      interface IntEnum { //warn
      }
  
      class InnerClass {
  
          public static final double FOO_PI_INNER = 3.1415;
          private boolean flagInner = true;
          { //warn
              //empty instance initializer
          }
  
          private InnerClass()
          {
              //empty
          }
  
      }
  
      class InnerClass2 { //ok
          private InnerClass2() //ok
          {
              //empty
          }
      }
  
      class InnerClass3 { //ok
          public int compareTo(InputEmptyLineSeparator aObject) //ok
          {
              int number = 0;
              return 0;
          }
  
      }
  }
  
  class Clazz { //ok
      private Clazz() {} //ok
  }
  class Class2{ //warn
      public int compareTo(InputEmptyLineSeparator aObject) //ok
      {
          int number = 0;
          return 0;
      }
      Class2 anon = new Class2(){ //warn
          public int compareTo(InputEmptyLineSeparator aObject) //ok
          {
              int number = 0;
              return 0;
          }
      };
  }
  