void DrawLine(int x1, int y1, int x2, int y2) {
public void DrawLine(int x1, int y1, int x2, int y2) {
void DrawLine(int x1, int y1, int x2, int y2) {    b.drawLine(x1, y1, x2, y2);    a.drawLine(x1, y1, x2, y2);}