Design a class Line that implements a line, which is represented by the formula y = ax+b. Your class should store a and b as double member variables. Write a member function intersect(ℓ) that returns the x coordinate at which this line intersects line ℓ. If the two lines are parallel, then your function should throw an exception Parallel. Write a C++ program that creates a number of Line objects and tests each pair for intersection. Your program should print an appropriate error message for parallel lines.