Test coverage: Check for the content of the original version in the request result

[sabina-talipova]

Description

VersionFeedFunctionalTest::testChangesActionContainsChangesForCurrentPageOnly test should check additionally for the content of the original version in the request result.
See

silverstripe-versionfeed/tests/VersionFeedFunctionalTest.php

Lines 168 to 190 in c4ba8bf

	public function testChangesActionContainsChangesForCurrentPageOnly()
	{
	$page1 = $this->createPageWithChanges(['Title' => 'Page1']);
	$page2 = $this->createPageWithChanges(['Title' => 'Page2']);
	$response = $this->get($page1->RelativeLink('changes'));
	$xml = simplexml_load_string($response->getBody());
	$titles = array_map(function ($item) {
	return (string)$item->title;
	}, $xml->xpath('//item'));
	// TODO Unclear if this should contain the original version
	$this->assertContains('Changed: Page1', $titles);
	$this->assertNotContains('Changed: Page2', $titles);
	$response = $this->get($page2->RelativeLink('changes'));
	$xml = simplexml_load_string($response->getBody());
	$titles = array_map(function ($item) {
	return (string)$item->title;
	}, $xml->xpath('//item'));
	// TODO Unclear if this should contain the original version
	$this->assertNotContains('Changed: Page1', $titles);
	$this->assertContains('Changed: Page2', $titles);
	}