Student keeps track of all the domains a student is logged into
as well as the domains that the student is able to log into, and their
userName and password which the student uses to log into domains.
The constructor sorts out the arguments, then hands
over the DOM work to the DOM parser; which is used to build
the DOM tree and then parse the student model docs (.xml).
The constructor sorts out the arguments, then hands
over the DOM work to the DOM parser; which is used to build
the DOM tree and then parse the student model docs (.xml).