title: Count how many HashMap entries have a given value
body: <pre><code>public final static HashMap&lt;String, Integer&gt; party = new HashMap&lt;String, Integer&gt;();
  party.put("Jan",1);
  party.put("John",1);
  party.put("Brian",1);
  party.put("Dave",1);
  party.put("David",2);
  </code></pre>
  
  <p>How can I return a number of <strong>how many people</strong> has the value <strong>1</strong></p>