快乐是无法定义的，但却可以在一个人的骨子里和身体里感受到。
Joy cannot be defined but is felt in one's bones and substance.
所有的参赛队员除了守门员都是法定盲人，球里放有鹅卵石，那么队员可以知道球的位置。
All of the players are legally blind, except for the goal keeper, and the soccer ball has pebbles in it so the players can tell where it is.
在这个例子里，这个结构类型由一个有着特定签名的方法定义。
In this case, the structural type is defined by a method with a particular signature.
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