public function testIsCached()
{
$pc = new PageCache(__DIR__ . '/config_test.php');
$pc->setPath(vfsStream::url('tmpdir') . '/');
//no cache exists
$this->assertFalse($pc->isCached(), ' is cached');
$this->assertFalse(file_exists($pc->getFilePath()), 'file exists');
//cache page
$pc->init();
$output = 'testIsCached() being test... this line is going to populate cache file for testing...';
echo $output;
//manually end output buffering. file cache must exist
ob_end_flush();
//cache exists now
$this->assertTrue($pc->isCached());
$this->assertTrue(file_exists($pc->getFilePath()), __METHOD__ . ' after init cache file does not exist');
$this->assertEquals($output, file_get_contents($pc->getFilePath()), 'Cache file contents not as expected.');
}