title: CAS-6-Forgot username unable to sent user name in mail
body: <p>I am new in CAS-6 and trying to send user name in mail, I created &quot;forgot.password.gtemplat&quot; file for email.
  In template I am trying to get username from attribute using this syntax &quot;<strong>&lt;%=principal.attributes.username %&gt;&quot;</strong>, <strong>&quot;&lt;%=email %&gt;&quot;</strong>
  value of email is email address entered by user this returns proper value but value of <strong>&lt;%=principal.attributes.username %&gt;</strong> &quot; is printing null, I didn't understand why, In console it says &quot;None of the principal resolvers in the chain were able to produce a principal&quot;.
  For attribute resolution I am calling rest API.</p>