These each take the form of a type parameter name followed by the field descriptors for the class bound and interface bounds (if any) of the type.
这些定义的形式都相同，类型参数名称后接类型的类边界和接口边界(若存在)的字段描述符。
2
So, casts to type parameters will turn into casts to the upper boundof the parameter.
因此，对类型参数的数据类型转换将变成对参数上界的转换。
3
To increase the usefulness of our generic code, instead of specifying the exact type of a generic type parameter, we can specify an upper (or lower) bound instead.