protected function tempDir($fill = false)
{
$testDir = $this->createTempSubDir();
if ($fill) {
touch($testDir . '/test-file');
mkdir($testDir . '/test-dir');
touch($testDir . '/test-dir/test-file');
mkdir($testDir . '/test-nesting/1/2/3', 0755, true);
touch($testDir . '/test-nesting/1/2/3/test-file');
}
return $testDir;
}