[FEATURE] Generate unique value to struct's fields.

[donnol]

type User struct {
        Id             int               // unique value in this struct, like: 1.
        Age          int               // unique value in this struct, other value except 1, like: 2.
        Name      string           // unique value in this struct, like: "Jack".
        Phone      string          // unique value in this struct, other vlaue except "Jack".
}