const mirrorSide = sideBoard[0][kp[0]][kp[1]] != VariantRules.EMPTY ? 1 : 2;
let saveBoard = this.board;
this.board = sideBoard[mirrorSide-1];
const mirrorSide = sideBoard[0][kp[0]][kp[1]] != VariantRules.EMPTY ? 1 : 2;
let saveBoard = this.board;
this.board = sideBoard[mirrorSide-1];