[web2py] how to display the value of a reference field, instead of the id in sqlform.grid

[dave]

grid = SQLFORM.grid(query, args=[request.args(0)],
                                    fields=[db.auth_user.test0, 
                                    db.auth_user.test1, 
                                    db.auth_user.test2,
I have defined this in my controller, the value of test1 is a reference to 
another table, how would I make web2py show the referenced value instead of 
displaying the id, something equivalent to Field('field2', 'reference 
employees', requires=IS_IN_DB(db, 'employees.id', '%(name)s')) when 
defining the table

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