title: Map which allows duplicate key as well as maintain insertion order
body: <p>Currently I am using LinkedHashMap which maintain the insertion order.</p>
  
  <p>Syntax for LinkedHashMap which I used :</p>
  
  <pre><code>private LinkedHashMap&lt;String, String&gt; linkedHashMap = new LinkedHashMap&lt;String, String&gt;();
  linkedHashMap.put("R1", "Data1");   
  linkedHashMap.put("R2", "Data2");
  linkedHashMap.put("R3", "Data3");
  linkedHashMap.put("R4", "Data4");
  </code></pre>
  
  <p>Which is working fine. But I have where I have to used duplicate key and also I have maintain the insertion data.</p>
  
  <p>For example :</p>
  
  <pre><code>private LinkedHashMap&lt;String, String&gt; linkedHashMap = new LinkedHashMap&lt;String, String&gt;();
  linkedHashMap.put("R1", "Data1");   
  linkedHashMap.put("R2", "Data2");
  linkedHashMap.put("R1", "Data3");
  linkedHashMap.put("R2", "Data4");
  </code></pre>
  
  <p>When I am trying to keep duplicate data in linkedHaphMap then its removed duplicate data and keep only one data.</p>
  
  <p>So How can I insert duplicate data and maintain the insertion order in java? What is the way to achieve my case?</p>