'Add a Last Name field to a form description.
Arguments:
form_desc: A form description
Keyword Arguments:
required (bool): Whether this field is required; defaults to False'

def _add_last_name_field(self, form_desc, required=False):

    last_name_label = _(u'Last    Name')
    form_desc.add_field('last_name', label=last_name_label, required=required)
