create a unique variable name for use in a URL.
Name of the variable to have prefixed.
Create a namespaced request parameter for use in a URL.
The provided name is prefixed with a string unique to the file to be used in URL query parameters.
The purpose of prefixing variables is applying a namespace so that parameters can be passed to individual applications instead of all of them. This way there may be 2 instances of the same application on the same page without having conflicts.
It is guaranteed that calling .prefixVar() on two different files of
the same website will return different results. Think of addressing
the parameters to specific targets.
Creating 2 unique request parameters addressed to separate files.