1. Create JSF 2 KickStart project.
2. Open User.java
3. Add the following method to the class:

public List<String> getString() {
    return new ArrayList<String>();
}

4. Open inputname.xhtml
5. Add the following method to the page:

<h:dataTable value="#{user.string}" var="test">
        <h:outputText value="#{test.broken}" />
</h:dataTable>

6. Save the file.
7. ASSERT: "broken" is marked with warning that it cannot be resolved.
FAILURE: "broken" is marked only if you enable validation of EL variables (Windows->Preferences->JBoss Tools->Web->Expression Lenguage->Validation->Variable cannot be resolved->Warning).