Help with Third Party Library phpmailer

I have been watching the PHP Development section and have been following along but typing my own code instead of using the code that is provided. I'm doing this to see if i truly understand what is happening and it has been going great so far but i have run into trouble on the Using a Third-Party Library video. I went to the exact link in the video and downloaded the phpmailer. When i tried to include it in to my website i noticed that it was javascript not php. I then went to the github for phpmailer and downloaded it. This one was actually php but it was a different version. It has similar but slightly different names for all the functions and methods and i cant find the right ones the work like the ones in the video (i have looked for hours lol and it doesnt have the specific thing i need on the github info page) I am currently looking for the ValidAddress(). I was wondering if anybody could point me to the version that is used in the video or is it just too outdated. It is 5.2 if i can remember right.