Set<Action> (@NotNull String category, @NotNull String message, String @NotNull [] details, @Nullable Throwable t) { Assert.assertNotNull("Unexpected error without Throwable: " + message, t); if (!error.compareAndSet(null, t)) { Assert.fail("Multiple errors were reported: " + error.get().getMessage() + " and " + t.getMessage()); } return Action.NONE; }