kernel/lib/Cache/File.php
public function delete(string $sName)
    {
        return unlink($this->_sFolder.$this->_getSubDirectory($sName).md5($sName).'.fil.cac');
    }
public function delete(string $sName)
    {
        return unlink($this->_sFolder.$this->_getSubDirectory($sName).md5($sName).'.fil.cac');
    }
delete a value

@access public
@param  string $sName name of the session
@return mixed