/**
  * isMobile
  * 
  * Checks and return state of mobile device detected
  * 
  * @return boolean
  * @since 3.4.2
  */
 public function isMobile()
 {
     if (!$this->mobile_checked) {
         $this->mobile_checked = true;
         $mobile_detect = new ESSB_Mobile_Detect();
         $this->is_mobile = $mobile_detect->isMobile();
         $this->is_tablet = $mobile_detect->isTablet();
         if ($this->optionsBoolValue('mobile_exclude_tablet') && $this->is_tablet) {
             $this->is_mobile = false;
         }
         return $this->is_mobile;
     } else {
         return $this->is_mobile;
     }
 }