1// 2pub mod v1; 3pub mod v2; 4pub mod v3; 5 6// 7pub trait Version {} 8 9pub struct VersionV1; 10impl Version for VersionV1 {} 11 12pub struct VersionV2; 13impl Version for VersionV2 {} 14 15pub struct VersionV3; 16impl Version for VersionV3 {}