traversal

基本解释

This brings us to the concept of focus traversal hierarchy, and therefore of up and down focus cycles.
这让我们理解了焦点遍历层次结构的概念，从而明白了向上和向下的焦点循环的概念。
This is because traversal operators always return lists, even if there is only one item, or none, in the result.
这是因为遍历操作符总返回列表，即使结果中只有一个或没有项时也是如此。
This method can take another component as its argument, and will then transfer focus to the component that follows in the focus traversal cycle.
该方法可以把另一个组件作为它的参数，然后把焦点传递给焦点遍历循环中紧接着的那个组件。

What if there had been less shooting, and more puzzles and traversal?
FORBES: [Spoilers follow.]