field

type Config struct {
	Users map[string]*User `json:"users,omitempty"`
}

type S1 struct {
	Field1 S2
}

type S2 struct {
	Field2 string
	Field3 *string
	Field4 []string

	Field5 *S3

	Field6 []S3
}

type S3 struct {
	FieldA string
	FieldB string
}

type User struct {
	Token *string `json:"token,omitempty"`
}