After del1 + del2
Called ClassA.MethodA() with parameter: Hello World
Called ClassB.MethodB() with parameter: Hello World
After del1 + del2 + del3
Called ClassA.MethodA() with parameter: Hello World
Called ClassB.MethodB() with parameter: Hello World
Called lambda expression: Hello World
After del - del2
Called ClassA.MethodA() with parameter: Hello World
Called lambda expression: Hello World
After del1 - del1
Called lambda expression: Hello World