什么'；这是log4net.Config.XmlConfigurator（）的用途

我看到有人把log4net.Config.XmlConfigurator（）放在AssemblyInfo.cs中。它的具体用途是什么？

摘自：

// Configure log4net using the .config file
[assembly: log4net.Config.XmlConfigurator(Watch=true)]
// This will cause log4net to look for a configuration file
// called TestApp.exe.config in the application base
// directory (i.e. the directory containing TestApp.exe)
// The config file will be watched for changes.