It seems nuts to me that anyone would expect the Queen class to extend Bishop just because they happen to move diagonally. A Queen "IS NOT A" Bishop.
If anything, specify traits that define the movement of the pieces and have each piece extend that trait (with the Queen extending both CAN_MOVE_DIAGONALLY and CAN_MOVE_LATERALLY).
If anything, specify traits that define the movement of the pieces and have each piece extend that trait (with the Queen extending both CAN_MOVE_DIAGONALLY and CAN_MOVE_LATERALLY).