The type of the keys in the source object. 源对象中键的类型
The type of the values. 值的类型
A new object with mapped keys and the original values. 具有映射后键和原值的新对象
When multiple keys map to the same result key, the later entry wins (later
entries overwrite earlier ones), following Object.fromEntries order.
Mapped keys are created as own data properties, so mapping to __proto__
does not cause prototype pollution.
当多个键映射到同一个结果键时，后面的条目会覆盖前面的条目
（遵循 Object.fromEntries 的顺序）。映射后的键作为自身数据属性创建，
因此映射到 __proto__ 不会导致原型污染。
Maps the keys of an object and constructs a new object with the mapped keys.
Only own enumerable string keys are processed; symbol keys are ignored. The input object is not mutated.
映射对象的键，并构造一个具有映射后键的新对象。
仅处理自身可枚举的字符串键，符号键会被忽略。不会修改输入对象。