title: access a method in anther class which contain a private variables
body: <p>I have CreditCard class that contain a private variable </p>
  
  <pre><code>private double balance;
  </code></pre>
  
  <p>and a method charge like </p>
  
  <pre><code>public boolean charge(double price){
      if (price + balance &gt; limits)
          return false;
      balance += price;
      return true;
  }
  </code></pre>
  
  <p>Why the method charge in class <code>PredatoryCreditCard</code> flawed ??</p>
  
  <pre><code>public boolean charge(double price){
      boolean isSuccess = super.charge(price);
      if(!isSuccess)
          super.charge(5); //*** here the penalty
      return isSuccess;
  }
  </code></pre>
  
  <p>and even when we write <code>charge(5);</code> without super keyword flawed ??</p>