類的關系：?frame是個?WebSocketFrame?
public?abstract?class?WebSocketFrame?extends?DefaultByteBufHolder?

而WebSocketFrame?實現：
public?class?DefaultByteBufHolder?implements?ByteBufHolder?{
????private?final?ByteBuf?data;

????public?DefaultByteBufHolder(ByteBuf?data)?{
????????if?(data?==?null)?{
????????????throw?new?NullPointerException("data");
????????}?else?{
????????????this.data?=?data;
????????}
????}

????public?ByteBuf?content()?{
????????if?(this.data.refCnt()?<=?0)?{
????????????throw?new?IllegalReferenceCountException(this.data.refCnt());
????????}?else?{
????????????return?this.data;
????????}
????}

????public?ByteBufHolder?copy()?{
????????return?new?DefaultByteBufHolder(this.data.copy());
????}

????public?ByteBufHolder?duplicate()?{
????????return?new?DefaultByteBufHolder(this.data.duplicate());
????}

????public?int?refCnt()?{
????????return?this.data.refCnt();
????}

????public?ByteBufHolder?retain()?{
????????this.data.retain();
????????return?this;
????}

????public?ByteBufHolder?retain(int?increment)?{
????????this.data.retain(increment);
????????return?this;
????}

????public?boolean?release()?{
????????return?this.data.release();
????}

????public?boolean?release(int?decrement)?{
????????return?this.data.release(decrement);
????}

????public?String?toString()?{
????????return?StringUtil.simpleClassName(this)?+?'('?+?this.content().toString()?+?')';
????}
}

前一次回答里2個類名標注了粗體字，不知何故類名都不見了。

類的關系：
public?abstract?class??extends?DefaultByteBufHolder

public?class??implements?ByteBufHolder?{
????private?final?ByteBuf?data;

????public?DefaultByteBufHolder(ByteBuf?data)?{
????????if?(data?==?null)?{
????????????throw?new?NullPointerException("data");
????????}?else?{
????????????this.data?=?data;
????????}
????}

????public?ByteBuf?content()?{
????????if?(this.data.refCnt()?<=?0)?{
????????????throw?new?IllegalReferenceCountException(this.data.refCnt());
????????}?else?{
????????????return?this.data;
????????}
????}

????public?ByteBufHolder?copy()?{
????????return?new?DefaultByteBufHolder(this.data.copy());
????}

????public?ByteBufHolder?duplicate()?{
????????return?new?DefaultByteBufHolder(this.data.duplicate());
????}

????public?int?refCnt()?{
????????return?this.data.refCnt();
????}

????public?ByteBufHolder??{
????????this.data.retain();
????????return?this;
????}

????public?ByteBufHolder?retain(int?increment)?{
????????this.data.retain(increment);
????????return?this;
????}

????public?boolean?release()?{
????????return?this.data.release();
????}

????public?boolean?release(int?decrement)?{
????????return?this.data.release(decrement);
????}

????public?String?toString()?{
????????return?StringUtil.simpleClassName(this)?+?'('?+?this.content().toString()?+?')';
????}
}