public function keysExist(array $keys)
    {
        foreach ($keys as $key) {
            if (!$this->keyExists($key)) {
                return false;
            }
        }
        return true;
    }
public function keysExist(array $keys)
    {
        foreach ($keys as $key) {
            if (!$this->keyExists($key)) {
                return false;
            }
        }
        return true;
    }
public function keysExist ( array $ keys ) { foreach ( $ keys as $ key ) { if ( ! $ this -> keyExists ( $ key ) ) { return false ; } } return true ; }
Returns true if a all keys exist false otherwise.

@param  array $keys
@return bool
Returns true if a all keys exist false otherwise .