diff --git a/build/phpunit.xml b/build/phpunit.xml
index cba02c8a..926eb8e7 100644
--- a/build/phpunit.xml
+++ b/build/phpunit.xml
@@ -37,6 +37,7 @@
             <file>../tests/testcases/PdfReaderExtended2Test.php</file>
             <file>../tests/testcases/PdfReaderXRechnungTest.php</file>
             <file>../tests/testcases/PdfReaderMultipleAttachmentsTest.php</file>
+            <file>../tests/testcases/PdfReaderExtGeneralTest.php</file>
         </testsuite>
         <testsuite name="PDFBuilder">
             <file>../tests/testcases/PdfBuilderEn16931Test.php</file>
diff --git a/make/genmethoddocs.php b/make/genmethoddocs.php
index 99a34f8d..cbe338d0 100644
--- a/make/genmethoddocs.php
+++ b/make/genmethoddocs.php
@@ -12,6 +12,7 @@
 use horstoeko\zugferd\ZugferdDocumentPdfBuilder;
 use horstoeko\zugferd\ZugferdDocumentPdfMerger;
 use horstoeko\zugferd\ZugferdDocumentPdfReader;
+use horstoeko\zugferd\ZugferdDocumentPdfReaderExt;
 use horstoeko\zugferd\ZugferdDocumentReader;
 use horstoeko\zugferd\ZugferdDocumentValidator;
 use horstoeko\zugferd\ZugferdKositValidator;
@@ -672,6 +673,9 @@ private function fixPhpType(string $string): string
         if (stripos($string, '[]') !== false) {
             $string = 'array';
         }
+        if (stripos($string, 'array<') === 0) {
+            $string = 'array';
+        }
         if ($string == '$this') {
             $string = 'static';
         }
@@ -719,6 +723,7 @@ public static function generate(array $classes, array $ignoreInheritance = [])
     ZugferdDocumentBuilder::class => dirname(__FILE__) . '/Class-ZugferdDocumentBuilder.md',
     ZugferdDocumentReader::class => dirname(__FILE__) . '/Class-ZugferdDocumentReader.md',
     ZugferdDocumentPdfReader::class => dirname(__FILE__) . '/Class-ZugferdDocumentPdfReader.md',
+    ZugferdDocumentPdfReaderExt::class => dirname(__FILE__) . '/Class-ZugferdDocumentPdfReaderExt.md',
     ZugferdDocumentPdfBuilder::class => dirname(__FILE__) . '/Class-ZugferdDocumentPdfBuilder.md',
     ZugferdDocumentPdfMerger::class => dirname(__FILE__) . '/Class-ZugferdDocumentPdfMerger.md',
     ZugferdDocumentValidator::class => dirname(__FILE__) . '/Class-ZugferdDocumentValidator.md',
diff --git a/src/ZugferdDocumentPdfReaderExt.php b/src/ZugferdDocumentPdfReaderExt.php
new file mode 100644
index 00000000..5efbefa7
--- /dev/null
+++ b/src/ZugferdDocumentPdfReaderExt.php
@@ -0,0 +1,320 @@
+<?php
+
+/**
+ * This file is a part of horstoeko/zugferd.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace horstoeko\zugferd;
+
+use Exception;
+use horstoeko\zugferd\exception\ZugferdFileNotFoundException;
+use horstoeko\zugferd\exception\ZugferdFileNotReadableException;
+use horstoeko\zugferd\exception\ZugferdNoPdfAttachmentFoundException;
+use horstoeko\zugferd\exception\ZugferdUnknownProfileException;
+use horstoeko\zugferd\exception\ZugferdUnknownProfileParameterException;
+use horstoeko\zugferd\exception\ZugferdUnknownXmlContentException;
+use JMS\Serializer\Exception\RuntimeException;
+use Smalot\PdfParser\Parser as PdfParser;
+
+/**
+ * Class representing the extended document reader for incoming PDF/A-Documents with
+ * attached XML data in BASIC-, EN16931- and EXTENDED profile. The Extended PDF reader
+ * reads also additinal attached documents from PDF
+ *
+ * @category Zugferd
+ * @package  Zugferd
+ * @author   D. Erling <horstoeko@erling.com.de>
+ * @license  https://opensource.org/licenses/MIT MIT
+ * @link     https://github.com/horstoeko/zugferd
+ */
+class ZugferdDocumentPdfReaderExt
+{
+    /**
+     * List of filenames which are possible for an attached XML-Invoice-Document in PDF
+     */
+    public const ATTACHMENT_FILENAMES = [
+        'ZUGFeRD-invoice.xml'/*1.0*/,
+        'zugferd-invoice.xml'/*2.0*/,
+        'factur-x.xml'/*2.1*/,
+        'xrechnung.xml'
+    ];
+
+    /**
+     * Identifier for a XML-Invoice-Docuemnt
+     */
+    private const ATTACHMENT_TYPE_XMLINVOICE = 0;
+
+    /**
+     * Identifier for an additional document
+     */
+    private const ATTACHMENT_TYPE_ADDITIONAL = 1;
+
+    /**
+     * Key of the type element in the internal attachment list
+     */
+    public const ATTACHMENT_KEY_TYPE = 'type';
+
+    /**
+     * Key of the content element in the internal attachment list
+     */
+    public const ATTACHMENT_KEY_CONTENT = 'content';
+
+    /**
+     * Key of the filename element in the internal attachment list
+     */
+    public const ATTACHMENT_KEY_FILENAME = 'filename';
+
+    /**
+     * Key of the filename element in the internal attachment list
+     */
+    public const ATTACHMENT_KEY_MIMETYPE = 'mimetype';
+
+    /**
+     * Array containing all the attached files found in PDF
+     *
+     * @var array<int, array{type: int, content: string, filename: string, mimetype: string}>
+     */
+    private $attachmentContentList = [];
+
+    /**
+     * (Hidden) Constructor
+     */
+    final protected function __construct()
+    {
+        $this->attachmentContentList = [];
+    }
+
+    /**
+     * Load a PDF file
+     *
+     * @param  string $pdfFilename Contains a full-qualified filename which must exist and must be readable
+     * @return ZugferdDocumentPdfReaderExt
+     * @throws ZugferdFileNotFoundException
+     * @throws ZugferdFileNotReadableException
+     * @throws Exception
+     */
+    public static function fromFile(string $pdfFilename): ZugferdDocumentPdfReaderExt
+    {
+        if (!file_exists($pdfFilename)) {
+            throw new ZugferdFileNotFoundException($pdfFilename);
+        }
+
+        $pdfContent = file_get_contents($pdfFilename);
+
+        if ($pdfContent === false) {
+            throw new ZugferdFileNotReadableException($pdfFilename);
+        }
+
+        return static::fromContent($pdfContent);
+    }
+
+    /**
+     * Load a PDF content string
+     *
+     * @param  string $pdfContent Contains the raw data of a PDF
+     * @return ZugferdDocumentPdfReaderExt
+     * @throws Exception
+     */
+    public static function fromContent(string $pdfContent): ZugferdDocumentPdfReaderExt
+    {
+        return (new ZugferdDocumentPdfReaderExt())->collectAttachmentsFromPdfContent($pdfContent);
+    }
+
+    /**
+     * Load a PDF file and return a ZugferDocumentReader-Instance
+     *
+     * @param  string $pdfFilename Contains a full-qualified filename which must exist and must be readable
+     * @throws Exception
+     * @throws RuntimeException
+     * @return ZugferdDocumentReader
+     * @throws ZugferdFileNotFoundException
+     * @throws ZugferdFileNotReadableException
+     * @throws ZugferdNoPdfAttachmentFoundException
+     * @throws ZugferdUnknownProfileException
+     * @throws ZugferdUnknownProfileParameterException
+     * @throws ZugferdUnknownXmlContentException
+     * @see    \horstoeko\zugferd\ZugferdDocumentPdfReader::readAndGuessFromFile() For a similar purpose in another context.
+     */
+    public static function readAndGuessFromFile(string $pdfFilename): ZugferdDocumentReader
+    {
+        return static::fromFile($pdfFilename)->resolveInvoiceDocumentReader();
+    }
+
+    /**
+     * Load a PDF content and return a ZugferDocumentReader-Instance
+     *
+     * @param  string $pdfContent Contains the raw data of a PDF
+     * @throws Exception
+     * @throws RuntimeException
+     * @return ZugferdDocumentReader
+     * @throws ZugferdNoPdfAttachmentFoundException
+     * @throws ZugferdUnknownXmlContentException
+     * @throws ZugferdUnknownProfileException
+     * @throws ZugferdUnknownProfileParameterException
+     * @see    \horstoeko\zugferd\ZugferdDocumentPdfReader::readAndGuessFromContent() For a similar purpose in another context.
+     */
+    public static function readAndGuessFromContent(string $pdfContent): ZugferdDocumentReader
+    {
+        return static::fromContent($pdfContent)->resolveInvoiceDocumentReader();
+    }
+
+    /**
+     * Returns a invoice document XML content from a PDF file
+     * similar to ZugferdDocumentPdfReader::getXmlFromContent
+     *
+     * @param  string $pdfFilename Contains a full-qualified filename which must exist and must be readable
+     * @return string
+     * @throws ZugferdFileNotFoundException
+     * @throws ZugferdFileNotReadableException
+     * @throws Exception
+     * @throws ZugferdNoPdfAttachmentFoundException
+     * @see    \horstoeko\zugferd\ZugferdDocumentPdfReader::getXmlFromFile() For a similar purpose in another context.
+     */
+    public static function getInvoiceDocumentContentFromFile(string $pdfFilename): string
+    {
+        return static::fromFile($pdfFilename)->resolveInvoiceDocumentContent();
+    }
+
+    /**
+     * Returns a invoice document XML content from a PDF content string
+     *
+     * @param  string $pdfContent Contains the raw data of a PDF
+     * @return string
+     * @throws Exception
+     * @throws ZugferdNoPdfAttachmentFoundException
+     * @see    \horstoeko\zugferd\ZugferdDocumentPdfReader::getXmlFromContent() For a similar purpose in another context.
+     */
+    public static function getInvoiceDocumentContentFromContent(string $pdfContent): string
+    {
+        return static::fromContent($pdfContent)->resolveInvoiceDocumentContent();
+    }
+
+    /**
+     * Returns all additional documents (except the invoice document) from a PDF file
+     *
+     * @param  string $pdfFilename Contains a full-qualified filename which must exist and must be readable
+     * @return array<int, array{type: int, content: string, filename: string, mimetype: string}>
+     * @throws ZugferdFileNotFoundException
+     * @throws ZugferdFileNotReadableException
+     * @throws Exception
+     */
+    public static function getAdditionalDocumentContentsFromFile(string $pdfFilename): array
+    {
+        return static::fromFile($pdfFilename)->resolveAdditionalDocumentContents();
+    }
+
+    /**
+     * Returns all additional documents (except the invoice document) from a PDF content string
+     *
+     * @param  string $pdfContent Contains the raw data of a PDF
+     * @return array<int, array{type: int, content: string, filename: string, mimetype: string}>
+     * @throws Exception
+     */
+    public static function getAdditionalDocumentContentsFromContent(string $pdfContent): array
+    {
+        return static::fromContent($pdfContent)->resolveAdditionalDocumentContents();
+    }
+
+    /**
+     * Returns an instance of ZugferdDocumentReader by a valid invoice attachment
+     *
+     * @return ZugferdDocumentReader
+     * @throws ZugferdNoPdfAttachmentFoundException
+     * @throws ZugferdUnknownXmlContentException
+     * @throws ZugferdUnknownProfileException
+     * @throws ZugferdUnknownProfileParameterException
+     * @throws RuntimeException
+     */
+    public function resolveInvoiceDocumentReader(): ZugferdDocumentReader
+    {
+        return ZugferdDocumentReader::readAndGuessFromContent($this->resolveInvoiceDocumentContent());
+    }
+
+    /**
+     * Returns the content as string if a valid invoice attachment was found, otherwise
+     * an exception will be raised
+     *
+     * @return string
+     * @throws ZugferdNoPdfAttachmentFoundException
+     */
+    public function resolveInvoiceDocumentContent(): string
+    {
+        $invoiceContent =
+            array_values(
+                array_filter(
+                    $this->attachmentContentList,
+                    function ($attachmentContentItem) {
+                        return $attachmentContentItem[ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE] === ZugferdDocumentPdfReaderExt::ATTACHMENT_TYPE_XMLINVOICE;
+                    }
+                )
+            );
+
+        if (empty($invoiceContent)) {
+            throw new ZugferdNoPdfAttachmentFoundException();
+        }
+
+        return $invoiceContent[0][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_CONTENT];
+    }
+
+    /**
+     * Returns a list of all additional attached documents except the invoice document
+     *
+     * @return array<int, array{type: int, content: string, filename: string, mimetype: string}>
+     */
+    public function resolveAdditionalDocumentContents(): array
+    {
+        return
+            array_values(
+                array_filter(
+                    $this->attachmentContentList,
+                    function ($attachmentContentItem) {
+                        return $attachmentContentItem[ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE] === ZugferdDocumentPdfReaderExt::ATTACHMENT_TYPE_ADDITIONAL;
+                    }
+                )
+            );
+    }
+
+    /**
+     * Get a list of all the attachments.
+     *
+     * @param  string $pdfContent Contains the raw data of a PDF
+     * @return ZugferdDocumentPdfReaderExt
+     * @throws Exception
+     */
+    protected function collectAttachmentsFromPdfContent(string $pdfContent): ZugferdDocumentPdfReaderExt
+    {
+        $this->attachmentContentList = [];
+
+        $pdfParser = new PdfParser();
+        $pdfParsed = $pdfParser->parseContent($pdfContent);
+        $fileSpecs = $pdfParsed->getObjectsByType('Filespec');
+
+        $fileSpecs = array_filter(
+            $fileSpecs,
+            function ($fileSpec) {
+                return $fileSpec->has('F') && $fileSpec->has('EF');
+            }
+        );
+
+        $fileSpecs = array_filter(
+            $fileSpecs,
+            function ($fileSpec) {
+                return $fileSpec->get('EF')->has('F');
+            }
+        );
+
+        foreach ($fileSpecs as $fileSpec) {
+            $this->attachmentContentList[] = [
+                ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE => in_array($fileSpec->get('F')->getContent(), ZugferdDocumentPdfReaderExt::ATTACHMENT_FILENAMES) ? ZugferdDocumentPdfReaderExt::ATTACHMENT_TYPE_XMLINVOICE : ZugferdDocumentPdfReaderExt::ATTACHMENT_TYPE_ADDITIONAL,
+                ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_CONTENT => $fileSpec->get('EF')->get('F')->getContent(),
+                ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_FILENAME => $fileSpec->get('F')->getContent(),
+                ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_MIMETYPE => $fileSpec->get('EF')->get('F')->has('Subtype') ? (string)($fileSpec->get('EF')->get('F')->get('Subtype')->getContent()) : "",
+            ];
+        }
+
+        return $this;
+    }
+}
diff --git a/tests/testcases/PdfReaderExtGeneralTest.php b/tests/testcases/PdfReaderExtGeneralTest.php
new file mode 100644
index 00000000..2d1f1b43
--- /dev/null
+++ b/tests/testcases/PdfReaderExtGeneralTest.php
@@ -0,0 +1,179 @@
+<?php
+
+namespace horstoeko\zugferd\tests\testcases;
+
+use horstoeko\zugferd\exception\ZugferdExceptionCodes;
+use horstoeko\zugferd\exception\ZugferdFileNotFoundException;
+use horstoeko\zugferd\exception\ZugferdNoPdfAttachmentFoundException;
+use horstoeko\zugferd\tests\TestCase;
+use horstoeko\zugferd\ZugferdDocument;
+use horstoeko\zugferd\ZugferdDocumentPdfReaderExt;
+use horstoeko\zugferd\ZugferdDocumentReader;
+
+class PdfReaderExtGeneralTest extends TestCase
+{
+    public function testReadFromFileWhichDoesNotExist(): void
+    {
+        $this->expectException(ZugferdFileNotFoundException::class);
+
+        ZugferdDocumentPdfReaderExt::readAndGuessFromFile(dirname(__FILE__) . "/../assets/unknown.pdf");
+    }
+
+    public function testReadFromFileWhichHasNoValidAttachment(): void
+    {
+        $this->expectException(ZugferdNoPdfAttachmentFoundException::class);
+        $this->expectExceptionMessage('No PDF attachment found');
+        $this->expectExceptionCode(ZugferdExceptionCodes::NOPDFATTACHMENTFOUND);
+
+        ZugferdDocumentPdfReaderExt::readAndGuessFromFile(dirname(__FILE__) . "/../assets/pdf_invalid.pdf");
+    }
+
+    public function testReadFromFileWhichExistsAndHasValidAttachment(): void
+    {
+        $document = ZugferdDocumentPdfReaderExt::readAndGuessFromFile(dirname(__FILE__) . "/../assets/pdf_zf_en16931_1.pdf");
+
+        $this->checkDocumentReader($document);
+    }
+
+    public function testReadFromContentWhichHasNoValidAttachment(): void
+    {
+        $this->expectException(ZugferdNoPdfAttachmentFoundException::class);
+        $this->expectExceptionMessage('No PDF attachment found');
+        $this->expectExceptionCode(ZugferdExceptionCodes::NOPDFATTACHMENTFOUND);
+
+        $pdfContent = file_get_contents(dirname(__FILE__) . "/../assets/pdf_invalid.pdf");
+
+        ZugferdDocumentPdfReaderExt::readAndGuessFromContent($pdfContent);
+    }
+
+    public function testReadFromContentWhichHasValidAttachment(): void
+    {
+        $pdfContent = file_get_contents(dirname(__FILE__) . "/../assets/pdf_zf_en16931_1.pdf");
+
+        $document = ZugferdDocumentPdfReaderExt::readAndGuessFromContent($pdfContent);
+
+        $this->checkDocumentReader($document);
+    }
+
+    public function testGetXmlFromFileWhichDoesNotExist(): void
+    {
+        $this->expectException(ZugferdFileNotFoundException::class);
+
+        ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromFile(dirname(__FILE__) . "/../assets/unknown.pdf");
+    }
+
+    public function testGetXmlFromFileWhichHasNoValidAttachment(): void
+    {
+        $this->expectException(ZugferdNoPdfAttachmentFoundException::class);
+        $this->expectExceptionMessage('No PDF attachment found');
+        $this->expectExceptionCode(ZugferdExceptionCodes::NOPDFATTACHMENTFOUND);
+
+        ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromFile(dirname(__FILE__) . "/../assets/pdf_invalid.pdf");
+    }
+
+    public function testGetXmlFromFileWhichExistsAndHasValidAttachment(): void
+    {
+        $xmlString = ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromFile(dirname(__FILE__) . "/../assets/pdf_zf_en16931_1.pdf");
+
+        $this->checkInvoiceDocumentXml($xmlString);
+    }
+
+    public function testGetXmlFromContentWhichHasNoValidAttachment(): void
+    {
+        $this->expectException(ZugferdNoPdfAttachmentFoundException::class);
+        $this->expectExceptionMessage('No PDF attachment found');
+        $this->expectExceptionCode(ZugferdExceptionCodes::NOPDFATTACHMENTFOUND);
+
+        $pdfContent = file_get_contents(dirname(__FILE__) . "/../assets/pdf_invalid.pdf");
+
+        ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromContent($pdfContent);
+    }
+
+    public function testGetXmlFromContentWhichHasValidAttachment(): void
+    {
+        $pdfContent = file_get_contents(dirname(__FILE__) . "/../assets/pdf_zf_en16931_1.pdf");
+
+        $xmlString = ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromContent($pdfContent);
+
+        $this->checkInvoiceDocumentXml($xmlString);
+    }
+
+    public function testAdditionalAttachments(): void
+    {
+        $filename = dirname(__FILE__) . "/../assets/pdf_zf_en16931_2.pdf";
+
+        $xmlString = ZugferdDocumentPdfReaderExt::getInvoiceDocumentContentFromFile($filename);
+
+        $this->checkInvoiceDocumentXml($xmlString);
+
+        $additionalDocuments = ZugferdDocumentPdfReaderExt::getAdditionalDocumentContentsFromFile($filename);
+
+        $this->checkAdditionalAttachments($additionalDocuments);
+
+        $pdfContent = file_get_contents($filename);
+        $additionalDocuments = ZugferdDocumentPdfReaderExt::getAdditionalDocumentContentsFromContent($pdfContent);
+
+        $this->checkAdditionalAttachments($additionalDocuments);
+    }
+
+    public function testInvoiceDocumentAndAttachmentsNoStatic(): void
+    {
+        $pdfReaderExt = ZugferdDocumentPdfReaderExt::fromFile(dirname(__FILE__) . "/../assets/pdf_zf_en16931_2.pdf");
+
+        $documentReader = $pdfReaderExt->resolveInvoiceDocumentReader();
+
+        $this->checkDocumentReader($documentReader);
+
+        $xmlString = $pdfReaderExt->resolveInvoiceDocumentContent();
+
+        $this->checkInvoiceDocumentXml($xmlString);
+
+        $additionalDocuments = $pdfReaderExt->resolveAdditionalDocumentContents();
+
+        $this->checkAdditionalAttachments($additionalDocuments);
+    }
+
+    private function checkDocumentReader($documentReader): void
+    {
+        $this->assertNotNull($documentReader);
+        $this->assertInstanceOf(ZugferdDocument::class, $documentReader);
+        $this->assertInstanceOf(ZugferdDocumentReader::class, $documentReader);
+    }
+
+    private function checkInvoiceDocumentXml($xmlString): void
+    {
+        $this->assertNotNull($xmlString);
+        $this->assertIsString($xmlString);
+        $this->assertStringContainsString("<?xml version='1.0'", $xmlString);
+        $this->assertStringContainsString("<rsm:CrossIndustryInvoice", $xmlString);
+        $this->assertStringContainsString("</rsm:CrossIndustryInvoice>", $xmlString);
+    }
+
+    private function checkAdditionalAttachments($additionalDocuments): void
+    {
+        $this->assertNotEmpty($additionalDocuments);
+        $this->assertCount(2, $additionalDocuments);
+        $this->assertArrayHasKey(0, $additionalDocuments);
+        $this->assertArrayHasKey(1, $additionalDocuments);
+        $this->assertArrayNotHasKey(2, $additionalDocuments);
+        $this->assertArrayNotHasKey(3, $additionalDocuments);
+
+        $this->assertIsArray($additionalDocuments[0]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE, $additionalDocuments[0]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_CONTENT, $additionalDocuments[0]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_FILENAME, $additionalDocuments[0]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_MIMETYPE, $additionalDocuments[0]);
+        $this->assertEquals(1, $additionalDocuments[0][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE]);
+        $this->assertEquals('Aufmass.png', $additionalDocuments[0][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_FILENAME]);
+        $this->assertEquals('image/png', $additionalDocuments[0][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_MIMETYPE]);
+
+        $this->assertIsArray($additionalDocuments[1]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE, $additionalDocuments[1]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_CONTENT, $additionalDocuments[1]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_FILENAME, $additionalDocuments[1]);
+        $this->assertArrayHasKey(ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_MIMETYPE, $additionalDocuments[1]);
+        $this->assertEquals(1, $additionalDocuments[1][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_TYPE]);
+        $this->assertEquals('ElektronRapport.pdf', $additionalDocuments[1][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_FILENAME]);
+        $this->assertEquals('application/pdf', $additionalDocuments[1][ZugferdDocumentPdfReaderExt::ATTACHMENT_KEY_MIMETYPE]);
+    }
+}