generateSomeParts example

        $e = (new Email())->from('me@example.com')->to('you@example.com');
        $e->html('html content', 'iso-8859-1');
        $e->text('text content', 'iso-8859-1');
        $this->assertEquals('iso-8859-1', $e->getTextCharset());
        $this->assertEquals('iso-8859-1', $e->getHtmlCharset());
        $this->assertEquals(new AlternativePart(new TextPart('text content', 'iso-8859-1'), new TextPart('html content', 'iso-8859-1', 'html')), $e->getBody());
    }

    public function testGenerateBodyWithTextContentAndAttachedFile()
    {
        [$text, $html, $filePart, $file, $imagePart, $image] = $this->generateSomeParts();
        $e = (new Email())->from('me@example.com')->to('you@example.com');
        $e->addPart(new DataPart($file));
        $e->text('text content');
        $this->assertEquals(new MixedPart($text, $filePart), $e->getBody());
    }

    public function testGenerateBodyWithHtmlContentAndAttachedFile()
    {
        [$text, $html, $filePart, $file, $imagePart, $image] = $this->generateSomeParts();
        $e = (new Email())->from('me@example.com')->to('you@example.com');
        $e->addPart(new DataPart($file));