title: Map throw error on duplicate insertion
body: <p>I am creating a Map with stores some data and i want the map to throw an exception if a duplicate value is tried to insert.</p>
  
  <pre><code>Map &lt;Integer, String&gt; temp;
  temp.put(1, "hi");
  temp.put(1, "hello");
  </code></pre>
  
  <p>Here this map should throw an error since a key '1' is already present. 
  It can throw an error or does not compile. 
  Is there any map which has said functionality?</p>