title: How to get multiple values for multiple keys from Hashmap in a single operation?
body: <p>I want to get values for more than one key using <code>HashMap</code>, for example:</p>
  
  <pre><code>HashMap&lt;Integer, String&gt; map = new HashMap&lt;Integer, String&gt;();
  map.put(1, "Hello");
  map.put(2, "World");
  map.put(3, "New");
  map.put(4, "Old");
  </code></pre>
  
  <p>Now I want to combine values for <code>1</code> and <code>2</code> and create a <code>List&lt;String&gt;</code> output.
  I can do this with 2 times get an operation or create one function that takes a key list and return a list of values.</p>
  
  <p>But is there any in-built <em>util</em> function that do the same job?</p>