public function key($key = null) {
		if($key === null) return $this->key;
		$this->key = $key;
		return $this;
	}
public function key($key = null) {
		if($key === null) return $this->key;
		$this->key = $key;
		return $this;
	}
public function key ( $ key = null ) { if ( $ key === null ) return $ this -> key ; $ this -> key = $ key ; return $ this ; }
Get or set Job key

@param string Job key
@return self/string
@author Luke Lanchester
Get or set Job key