@NotNull
  public UnhandledExceptions merge(@NotNull UnhandledExceptions other) {
    boolean unresolvedCalls = hasUnresolvedCalls || other.hasUnresolvedCalls;
    if (exceptions.isEmpty()) return other.withUnresolvedCalls(unresolvedCalls);
    if (other.exceptions.isEmpty()) return this.withUnresolvedCalls(unresolvedCalls);
    return new UnhandledExceptions(ContainerUtil.union(exceptions, other.exceptions), unresolvedCalls);
  }
@NotNull
  public UnhandledExceptions merge(@NotNull UnhandledExceptions other)