code: def get_parameter(self, twig=None, **kwargs):
          
          kwargs['twig'] = twig
          kwargs['check_default'] = False
          kwargs['check_visible'] = False
          ps = self.vars.filter(**kwargs)
          if len(ps)==1:
              return ps.get(check_visible=False, check_default=False)
          elif len(ps) > 1:
              # TODO: is this safe?  Some constraints may have a parameter listed
              # twice, so we can do this then, but maybe should check to make sure
              # all items have the same uniqueid?  Maybe check len(ps.uniqueids)?
              return ps.to_list()[0]
          else:
              raise KeyError("no result found")
docs: get a parameter from those that are variables