@NotNull
  public List<MavenArtifact> findArtifacts(@Nullable String groupId, @Nullable String artifactId, @Nullable String version) {
    Map<String, List<MavenArtifact>> groupMap = myData.get(groupId);
    if (groupMap == null) return Collections.emptyList();

    List<MavenArtifact> artifacts = groupMap.get(artifactId);
    if (artifacts == null) return Collections.emptyList();

    List<MavenArtifact> res = new SmartList<>();
    for (MavenArtifact artifact : artifacts) {
      if (Objects.equals(version, artifact.getVersion())) {
        res.add(artifact);
      }
    }

    return res;
  }
@NotNull
  public List<MavenArtifact> findArtifacts(@Nullable String groupId, @Nullable String artifactId, @Nullable String version)