public String getRegistrationUrl() {
   return Config.getAppUrl(Const.ActionURIs.STUDENT_COURSE_JOIN_NEW)
       .withRegistrationKey(StringHelper.encrypt(key))
       .withStudentEmail(email)
       .withCourseId(course)
       .toString();
 }
 public String getPublicProfilePictureUrl() {
   return Config.getAppUrl(Const.ActionURIs.STUDENT_PROFILE_PICTURE)
       .withStudentEmail(StringHelper.encrypt(email))
       .withCourseId(StringHelper.encrypt(course))
       .toString();
 }