Module20.cs

using System;

public class Module20
{
  int column1; // not yet explained why it is a column
  
  private void operation1 () // looks like nullary operation
  {
    Console.WriteLine (column1);
  }
  
  private void operation2 (/*Module20 this*/) 
  { // similar, looks like nullary operation
    Console.WriteLine (this.column1);
  }
  
  public static void Main (string[] args)
  {
    Module20 RecObject1 = new Module20();
    RecObject1.column1 = 1;
    Module20 RecObject2 = new Module20();
    RecObject2.column1 = 2;
    RecObject1.operation1(); // operation1 (RecObject1);
    RecObject2.operation1(); // operation1 (RecObject2);
    RecObject1.operation2(); // operation2 (RecObject1);
    RecObject2.operation2(); // operation2 (RecObject2);    
  }
}