public function offsetGet($offset)
    {
        return isset($this->_data[$offset]) ? $this->_data[$offset] : NULL;
    }
public function offsetGet($offset)
    {
        return isset($this->_data[$offset]) ? $this->_data[$offset] : NULL;
    }
public function offsetGet ( $ offset ) { return isset ( $ this -> _data [ $ offset ] ) ? $ this -> _data [ $ offset ] : NULL ; }
For \ArrayAccess interface

@param mixed $offset

@return bool
For \ ArrayAccess interface