code: public function Drop($key,$use=null) {
  	/*//
  	@argv string Key
  	@argv string Key, array Drivers
  	drop a specific key from the cache.
  	//*/
  
  		if(!$use)
  		$use = Option::Get('cache-drivers-use');
  
  		foreach($this->Drivers as $dkey => $driver) {
  			if(!in_array($dkey,$use)) continue;
  
  			$driver->Drop($this->GetFullKey($key));
  		}
  
  		return;
  	}
docs: //////////////