refresh_token_expires_in Doesn't populate.

[joshuacarino]

So I have the ff. code to get the attributes of the Refresh Token I passed.

var token_details ={
"Data" : {
     "access_token" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.access_token"),
     "scope" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.scope"),
 "expires_in" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.expires_in"),
 "status" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.status"),
 "client_id" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.client_id"),
     "refresh_token" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.refresh_token"),
 "refresh_token_status" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.refresh_token_status"),
 "refresh_token_expires_in" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.refresh_token_expires_in "),
   "refresh_count" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.refresh_count"),
     "refresh_token_issued_at" : context.getVariable("oauthv2refreshtoken.OA-ValidateRefreshToken.refresh_token_issued_at"),
     "CurrentTime" : Date.now()
 },
 "Link" :   {
     "Self" : context.getVariable("proxy.basepath")
 },
 "Meta": {     }
};
context.setVariable("token_details",JSON.stringify(token_details));

Problem is the refresh_token_expires_in variable doesn't populate at all even though the Refresh Token has an expiry. What could be the reason why?