The white list for the throttling policy was not being instantiated or populated. 
The white list for the throttling policy was not being instantiated or populated. 

This prevented white listing of endpoints within the web.config, such as the following:

    <whitelists>
      <!--Policy whitelist-->
      <add policyType="3" entry="/foo/" />
    </whitelists>
stefanprodan/WebApiThrottle,yonglehou/WebApiThrottle,yonglehou/WebApiThrottle,lollop-lp/WebApiThrottle,yonglehou/WebApiThrottle