Write a Circle class that has the following fields: 

• Radius: a double
• PI: a final double initialized with the value 3.14159

The class should have the following methods: 

• Constructor. Accepts the radius of the circle as an argument.
• Constructor. A no-arg constructor that sets the radius field to 0.0.
• SetRadius. A mutator method for the radius field.
• GetRadius. An accessor method for the radius field.
• GetArea. Returns the area of the circle, which is calculated as Area = PI * radius * radius
• GetDiameter. Returns the diameter of the circle, which is Calculated as Diameter = radius * 2
• GetCircumference. Returns the circumference of the circle, which is calculated as Circumference = 2 * PI * radius

Write a program that demonstrates the Circle class by asking the user for the circle’s radius, creating a Circle object, and then reporting the circle’s area, diameter, and circumference.