title: Itereate HashMap with HashSet as values
body: <p>I've got HashMap with HashSet as value
  How to iterate over it ti reseive result like:</p>
  
  <pre><code>   key1
     value1
     value2
     value3
     ...
     key2
     value1
     value2
     value3
     key3
     ...
  </code></pre>
  
  <p>I have something wrong in my code:</p>
  
  <pre><code>Map&lt;String, HashSet&lt;String&gt;&gt; remarksMap = new HashMap&lt;String, HashSet&lt;String&gt;&gt;();
  //...
  
  Iterator&lt;Map.Entry&lt;String, HashSet&lt;String&gt;&gt;&gt; itr1 = remarksMap.entrySet().iterator();
  Iterator&lt;String&gt; itr2 = itr1.next().getValue().iterator();
  
      while (itr1.hasNext()) {
  
          System.out.println(itr1.next().getKey());
  
          while (itr2.hasNext()) {
              System.out.println(itr2.next());
  
          }
      }
  </code></pre>
  
  <p>Currently receiving wrong result like:</p>
  
  <pre><code>key1
  value1
  value2
  value3
  key2
  key3
  key4
  ...
  </code></pre>