code: def srcmdl_xml(self, **kwargs):
          
          kwargs_copy = self.base_dict.copy()
          kwargs_copy.update(**kwargs)
          localpath = NameFactory.srcmdl_xml_format.format(**kwargs_copy)
          if kwargs.get('fullpath', False):
              return self.fullpath(localpath=localpath)
          return localpath
docs: return the file name for source model xml files