function getWhitespace($as_string = true) {
		$ws = array_keys($this->whitespace);
		return (($as_string) ? implode('', $ws) : $ws);
	}
function getWhitespace($as_string = true) {
		$ws = array_keys($this->whitespace);
		return (($as_string) ? implode('', $ws) : $ws);
	}
Returns whitespace characters as string/array
@param bool $as_string Should the result be a string or an array?
@return string|array
@see setWhitespace()