title: Count occurrences of an entry in a hashmap property of an entity in a list
body: <p>I've a <code>WorkflowTask</code> entity with a <code>Map&lt;String, Object&gt;</code> property.</p>
  
  <pre><code>public class WorkflowTask {
      private Map&lt;String, Object&gt; properties;
  }
  </code></pre>
  
  <p>The <code>Map</code> has an entry <code>bpm_status</code> which can have a value of <code>Not Yet Started</code>.</p>
  
  <p>I'm displaying a <code>List&lt;WorkflowTask&gt;</code> in a data table and checking for this entry like below:</p>
  
  <pre><code>&lt;p:dataTable value="#{inboxController.list}" var="task"&gt;
      &lt;p:column&gt;
          &lt;ui:fragment rendered="#{task.properties.bpm_status eq 'Not Yet Started'}"&gt;&lt;b&gt;#{msg.inbox_new_msg}&lt;/b&gt;
          &lt;/ui:fragment&gt;
      &lt;/p:column&gt;
  &lt;/p:dataTable&gt;
  </code></pre>
  
  <p>I'd like to show a counter with total occurrences of this map entry <code>bpm_status=Not Yet Started</code> in the list.</p>
  
  <pre><code>&lt;p&gt;Amount of new messages: #{inboxController.list.???}&lt;/p&gt;
  </code></pre>
  
  <p>How can I achieve this?</p>