public function offsetExists($key)
    {
        $this->executeBeforeCallback();

        if (isset($this->items[$key])) {
            return true;
        }

        return false;
    }
public function offsetExists($key)
    {
        $this->executeBeforeCallback();

        if (isset($this->items[$key])) {
            return true;
        }

        return false;
    }
public function offsetExists ( $ key ) { $ this -> executeBeforeCallback ( ) ; if ( isset ( $ this -> items [ $ key ] ) ) { return true ; } return false ; }
Determines if the given offset exists.

@param  string  $key
@return bool
Determines if the given offset exists .