setFlags(fenflags) {
// white a-castle, h-castle, black a-castle, h-castle
this.castleFlags = { w: [true, true], b: [true, true] };
setFlags(fenflags) {
// white a-castle, h-castle, black a-castle, h-castle
this.castleFlags = { w: [true, true], b: [true, true] };