title: How to declare & Initialize a HashMap that Contains A HashSet
body: <p>I am trying to read a Map that contains a string as a key, and a set as a value, how should I go about this? This is what I have got.</p>
  
  <pre><code>/**
   * A Class
   */
  public class Catalog
  {  
     private HashMap &lt;String , Set&lt;String&gt; varieties&gt; aCatalog;
  
     /**
      * Constructor for objects of class Catalog
      */
     public Catalog()
     {
        // initialise instance variables
        varieties = new HashSet&lt;&gt;();
        aCatalog = new HashMap&lt;String,varieties&gt;();
     }
  }
  </code></pre>
  
  <p>This isn't working, I looked at some similar questions but i couldn't find a solution.</p>
  
  <p>Thanks for the help guys!</p>