if (!File.Exists(xsdPath)) { this.logger.Log( LogLevel.Error, this.loggerTheme, "Could not find xsd file {0}.", xsdPath); throw new FileNotFoundException(xsdPath); } if (!File.Exists(xmlPath)) { this.logger.Log( LogLevel.Error, this.loggerTheme, "Could not find xml file {0}.", xmlPath); throw new FileNotFoundException(xmlPath); } this.configDirectory = Path.GetDirectoryName(Path.GetFullPath(xmlPath));

The if block checks if the xsd and xml file exists.
If not, it will throw an exception.
Then the directory of the xml file is saved to the configDirectory variable