Design a straight Line class, with four integer values, respectively the two endpoint coordinates, the constructor passed four integer values, or default is (0, 0) and (10, 10), the Line has different thickness, its value from 1 to 7, the default is 1, a function of the set and get the Line thickness, such as setting out of range, is set to 1, all of the Line have the same color, the color value is set to 0-16, the default value is 16, have set and get the color function, such as setting out of range, is set to 16, have calculation length of the straight Line method, programming, testing the Line class all of the features,
