package com.tutego.insel.solutions.util;

import java.util.*;

public class Keller
{
  private LinkedList<Object> list = new LinkedList<Object>();

  public boolean isEmpty()
  {
    return list.isEmpty();
  }

  public Object pop()
  {
    if ( !isEmpty() )
      return list.removeLast();
    else
      return null;
  }

  public void push( Object o )
  {
    list.addLast( o );
  }

  /**
   * Eine kleine Testfunktion
   */
  public static void main( String[] args )
  {
    Keller k = new Keller();

    k.push( "nett" );
    k.push( "bist" );
    k.pop();
    k.push( "Du" );
    System.out.println( k.pop() );
    System.out.println( k.isEmpty() );
    System.out.println( k.pop() );
    System.out.println( k.isEmpty() );
  }
}