single sign on with PHP and azure active directory

Hi,

    In your documentation,Web Single Sign-On with PHP and Azure Active Directory under Step3 point number 6 you have given that we have to include simpleSAML.php file and federation folder.I downloaded the federation folder from the link that you have given in prerequisites but you have not given any link for the simpleSAML.php file.Can you please suggest the link with all the necessary files that I have to include?

Thanks,

Geethanjali.