protected function _getMime($filename, $default = 'application/octet-stream') {
		if (!isset($this->_Mime)) {
			$this->_Mime = new Mime();
		}
		$mime = $this->_Mime->detectMimeType($filename);
		// Some environments falsely return the default too fast, better fallback to extension here
		if (!$mime || $mime === $default) {
			$ext = pathinfo($filename, PATHINFO_EXTENSION);
			$mime = $this->_Mime->getMimeTypeByAlias($ext);
		}
		return $mime;
	}