public function create_user_activation_link($user_id)
 {
     if ((int) $user_id) {
         $pass = wp_generate_password(10, false);
         $activation_code = md5($pass);
         if (!update_user_meta($user_id, 'rm_activation_code', $activation_code)) {
             return false;
         }
         $user_data_obj = new stdClass();
         $user_data_obj->user_id = $user_id;
         $user_data_obj->activation_code = $activation_code;
         $user_data_json = json_encode($user_data_obj);
         $user_data_enc = urlencode(RM_Utilities::enc_str($user_data_json));
         $user_activation_link = admin_url('admin-ajax.php') . '?action=rm_activate_user&user=' . $user_data_enc;
         return $user_activation_link;
     }
     return false;
 }
 private function sanitize_password($val)
 {
     return RM_Utilities::enc_str($val);
 }