Write an Area class to represent the area of a shape. It should store the value of the area in a member variable named squareKm(double). The variable’s value should be settable and retrievable using a property named SquareKm(it should not allow negative values to be set). The class must also publish a SuspiciousValueSet C# event which is emitted if a value larger than 100000 is set for the area. The event must provided both the old and the new values of the area.

Provide the complete c# source code of the Area class as well as a short code snippet that creates an instance of it, subscribers to the SuspiciousValueSet event and prints the amount by which the area changed. You may not use the specialized event types defined by the .NET framework, you must define your own.