title: How to resolve the findbug Sequence of calls to java.util.concurrent.ConcurrentHashMap may not be atomic
body: <p>Hi I am getting the bug "Sequence of calls to java.util.concurrent.ConcurrentHashMap may not be atomic " when i am running find bug in my project for the below code.</p>
  
  <pre><code>public static final ConcurrentHashMap&lt;String,Vector&lt;Person&gt;&gt; personTypeMap = new ConcurrentHashMap&lt;String, Vector&lt;Person&gt;&gt;();
  
      private static void setDefaultPersonGroup() {
  
  
          PersonDao crud = PersonDao.getInstance();
          List&lt;Person&gt; personDBList = crud.retrieveAll();
          for (Person person : personDBList) {
              Vector&lt;Person&gt; personTypeCollection = personTypeMap.get(person
                      .getGroupId());
              if (personTypeCollection == null) {
                  personTypeCollection = new Vector&lt;Person&gt;();
                  personTypeMap.put(personTypeCollection.getGroupId(),
                          personTypeCollection);
              }
              personTypeCollection.add(person);
          }
      }
  </code></pre>
  
  <p>I am facing the problem at the line
  personTypeMap.put(personTypeCollection.getGroupId(),
                          personTypeCollection);</p>
  
  <p>Can any one help me to resolve the problem.</p>