public function wasNeverCalled(): bool
    {
        if (count($this->invocations) > 0) {
            throw new CallAmountViolation(sprintf(
                    '%s was not expected to be called,'
                    . ' but actually called %d time(s).',
                    $this->invocations->name(),
                    count($this->invocations)
            ));
        }

        return true;
    }