public static bool TryGetHeroIdByArtifact(this UserArtifactData data, int artifactId, out int?heroId)
 {
     heroId = default;
     return(default);
 public static Artifact GetHeroSlotArtifact(this UserArtifactData data, int heroId, ArtifactKindId kindId) => default;
 public static Dictionary <ArtifactKindId, Artifact> GetHeroArtifacts(this UserArtifactData data, int heroId) => default;
 public static HeroArtifactData GetHeroArtifactData(this UserArtifactData data, int heroId) => default;
 // [IteratorStateMachine]
 public static IEnumerable <Artifact> GetFreeArtifacts(this UserArtifactData data) => default;
 public static Artifact Artifact(this UserArtifactData data, int with) => default;