In a triangle \( \triangle PQR \), the co-ordinates of the points \( P \) and \( Q \) are \( (-2, 4) \) and \( (4, -2) \) respectively. If the equation of the perpendicular bisector of \( PR \) is \( 2x - y + 2 = 0 \), then the centre of the circumcircle of \( \triangle PQR \) is:
