Implemented the ability to override the instance of ZipContainer.

ZipContainer will be cloned before writing the zip file.
Tested custom ZipWriter, ZipReader, ZipContainer and ZipFile.

tests/CustomZipFormatTest.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace PhpZip\Tests;
+
+use PhpZip\Exception\ZipEntryNotFoundException;
+use PhpZip\Exception\ZipException;
+use PhpZip\Tests\Internal\Epub\EpubFile;
+
+/**
+ * Checks the ability to create own file-type class, reader, writer and container.
+ *
+ * @see http://www.epubtest.org/test-books source epub files
+ *
+ * @internal
+ *
+ * @small
+ */
+final class CustomZipFormatTest extends ZipTestCase
+{
+    /**
+     * @throws ZipException
+     */
+    public function testEpub()
+    {
+        $epubFile = new EpubFile();
+        $epubFile->openFile(__DIR__ . '/resources/Advanced-v1.0.0.epub');
+        self::assertSame($epubFile->getRootFile(), 'EPUB/package.opf');
+        self::assertSame($epubFile->getMimeType(), 'application/epub+zip');
+        $epubInfo = $epubFile->getEpubInfo();
+        self::assertSame($epubInfo->toArray(), [
+            'title' => 'Advanced Accessibility Tests: Extended Descriptions',
+            'creator' => 'DAISY Consortium Transition to EPUB 3 and DIAGRAM Standards WG',
+            'language' => 'en-US',
+            'publisher' => 'DAISY Consortium and DIAGRAM Center',
+            'description' => 'Tests for accessible extended descriptions of images in EPUBs',
+            'rights' => 'This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike (CC BY-NC-SA) license.',
+            'date' => '2019-01-03',
+            'subject' => 'extended-descriptions',
+        ]);
+        $epubFile->deleteFromName('mimetype');
+        self::assertFalse($epubFile->hasEntry('mimetype'));
+
+        try {
+            $epubFile->getMimeType();
+            self::fail('deleted mimetype');
+        } catch (ZipEntryNotFoundException $e) {
+            self::assertSame('Zip Entry "mimetype" was not found in the archive.', $e->getMessage());
+        }
+        $epubFile->saveAsFile($this->outputFilename);
+        self::assertFalse($epubFile->hasEntry('mimetype'));
+        $epubFile->close();
+
+        self::assertCorrectZipArchive($this->outputFilename);
+
+        $epubFile->openFile($this->outputFilename);
+        // file appended in EpubWriter before write
+        self::assertTrue($epubFile->hasEntry('mimetype'));
+        $epubFile->close();
+    }
+}