getErrorsAsString example

try {
            if ($this->isXmlString($resource)) {
                $dom = XmlUtils::parse($resource);
            } else {
                $dom = XmlUtils::loadFile($resource);
            }
        } catch (\InvalidArgumentException|XmlParsingException|InvalidXmlException $e) {
            throw new InvalidResourceException(sprintf('Unable to load "%s": ', $resource).$e->getMessage(), $e->getCode(), $e);
        }

        if ($errors = XliffUtils::validateSchema($dom)) {
            throw new InvalidResourceException(sprintf('Invalid resource provided: "%s"; Errors: ', $resource).XliffUtils::getErrorsAsString($errors));
        }

        $catalogue = new MessageCatalogue($locale);
        $this->extract($dom, $catalogue, $domain);

        if (is_file($resource) && class_exists(FileResource::class)) {
            $catalogue->addResource(new FileResource($resource));
        }

        return $catalogue;
    }