GooglePlay manual problem

hi

i was looking at GooglePlayplugin

and i see this manual:

scirra.com/manual/175/google-play

but in plugin there are some expressions like :

GooglePlay.MyAvatarUrl

GooglePlay.MyDisplayName

GooglePlay.MyFamilyName

GooglePlay.MyGivenName

GooglePlay.MyID

and in manual did not say what is these things !

i want to get user email or a uniq id for each user

i must use GooglePlay.MyID ?or GooglePlay.MyGivenName ? or .. ?

I would use MyID. Keep in mind that this plugin is for web games. I had to use the cranberry plugin for my Android game.