Stateful transforms are simple objects with member functions that maintain state across calls:
!SourceBuffer.prototype.appendBuffer.toString().includes('[native code]')
，这一点在safew官方下载中也有详细论述
const len = nums.length;
If a player gets all four words in a set correct, those words are removed from the board. Guess wrong and it counts as a mistake—players get up to four mistakes until the game ends.