title: What is difference between HashMap and HashMultimap
body: <p>I see many examples about multimap but did not understand why Google Gauva is different?</p>
  
  <pre><code>Multimap&lt;Integer, Set&lt;String&gt;&gt; option4 = HashMultimap.create(); // Gauva
  
  Map&lt;Integer, Set&lt;String&gt;&gt; opt = new HashMap&lt;Integer, Set&lt;String&gt;&gt;(); //Core Java
  </code></pre>
  
  <p>Is both above are behave same for holding data or different? </p>