public function getdifficulty()
 {
     $this->oDebug->append("STA " . __METHOD__, 4);
     if ($data = $this->memcache->get(__FUNCTION__)) {
         return $data;
     }
     $data = parent::getdifficulty();
     // Check for PoS/PoW coins
     if (is_array($data) && array_key_exists('proof-of-work', $data)) {
         $data = $data['proof-of-work'];
     }
     return $this->memcache->setCache(__FUNCTION__, $data, 30);
 }