public static Map<InferenceVariable, Set<InferenceVariable>> getDependencies(
    Collection<? extends InferenceVariable> vars, InferenceSession session) {

    Map<InferenceVariable, Set<InferenceVariable>> map = new HashMap<>();
    for (InferenceVariable var : vars) {
      map.put(var, var.getDependencies(session));
    }
    return map;
  }
public static Map<InferenceVariable, Set<InferenceVariable>> getDependencies(
    Collection<? extends InferenceVariable> vars, InferenceSession session)