public PackageGroup(string postfix)
{
var className = $"PackageVersions{postfix}";
var outputPackageVersionsPropsFilename = Path.Combine(_solutionDirectory, $"PackageVersions{postfix}.g.props");
var outputPackageVersionsXunitFilename = Path.Combine(
_baseXunitPath,
$"PackageVersions{postfix}.g.cs");
_msBuildPropsFileGenerator = new MSBuildPropsFileGenerator(outputPackageVersionsPropsFilename);
_xUnitFileGenerator = new XUnitFileGenerator(outputPackageVersionsXunitFilename, className);
}