Once input data is wrapped by the WrapData function, it is somewhat involved to rename a variable
inside. This function makes it easier to do so.
Given an variable named InputVar and the name one wishes to rename it to, OutputVar, the
rename command options are:
xformInfo="InputVar -> OutputVar"
There are two methods in which the variables can be referred to. The first method is to use its
column number; given the data attribute of the boxData object, this would be the order at
which the variable appears. This can be indicated in the format "column#". The second method is to
refer to the variable by its name. This method will work even if the renamed value already exists; in
which case there will be two variables with the same name.
If no input variable name is provided, the original object is returned with no renamings performed.