title: WSO2 IS - Oauth SP + UserStore restriction
body: <p>I have an OAuth2 service provider with password credentials in WSO2 IS and I need that just users from a userStore can get a token. I have tried using XACML policies with now success.</p>
  <p>Is it possible to deny the OAuth token request per userStore?</p>
  <p>Cheers.</p>