code: def corners(self):
          
  
          corners = [(-self.width/2, -self.height/2),
                     ( self.width/2, -self.height/2),
                     ( self.width/2,  self.height/2),
                     (-self.width/2,  self.height/2),
                    ]
          rotmat = [[np.cos(self.angle), np.sin(self.angle)],
                    [-np.sin(self.angle), np.cos(self.angle)]]
  
          return np.dot(corners, rotmat) + np.array([self.center.x,
                                                     self.center.y])
docs: Return the x, y coordinate pairs that define the corners