code: def _attach_fulltext(self, rec, doi):
          
          url = os.path.join(self.url_prefix, doi)
          record_add_field(rec, 'FFT',
                           subfields=[('a', url),
                                      ('t', 'INSPIRE-PUBLIC'),
                                      ('d', 'Fulltext')])
docs: Attach fulltext FFT.