Why does Flash Builder 4.7 not allow code hinting for components like CheckBox?

<?xml version="1.0" encoding="utf-8"?>

<s:WindowedApplication xmlns:fx="http://ift.tt/rYUnH9" 
                   xmlns:s="library://ns.adobe.com/flex/spark" 
                   initialize="init()"
                   xmlns:mx="library://ns.adobe.com/flex/mx">
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>

    <s:VGroup id="content">
        <s:VGroup id="sizes">
            <!-- I added the CheckBox, but code hints are absent-->
            <s:CheckBox width="100" label="Employee?"/> 
        </s:VGroup>
    </s:VGroup>

</s:WindowedApplication>

The only way you know the CheckBox exists is by running the document. No indication that it's even available.