title: c# custom attribute for a method parameter - how it works?
body: <p>I would like to understand how this particular case works. Here is the shot from msdn article where INotifyPropertyChanged interface is explained (<a href="https://msdn.microsoft.com/query/dev12.query?appId=Dev12IDEF1&amp;l=EN-US&amp;k=k%28System.ComponentModel.INotifyPropertyChanged%29;k%28TargetFrameworkMoniker-.NETFramework,Version%3Dv4.5%29;k%28DevLang-csharp%29&amp;rd=true" rel="noreferrer">https://msdn.microsoft.com/query/dev12.query?appId=Dev12IDEF1&amp;l=EN-US&amp;k=k%28System.ComponentModel.INotifyPropertyChanged%29;k%28TargetFrameworkMoniker-.NETFramework,Version%3Dv4.5%29;k%28DevLang-csharp%29&amp;rd=true</a>)
  <a href="https://i.stack.imgur.com/CUXyJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/CUXyJ.png" alt="enter image description here"></a></p>
  
  <p>As it's said in marked lines there is a way of intercepting method call to substitute a value instead of what is actual goes as a parameter?
  I would like to get an idea of what the code to do this looks like. I know how to work with attributes set for properties and other class members but this use case is not clear for me.</p>
  
  <p>Thanks.</p>