code: def _build_amendment_id(self, json_repr):
          
          amendment = self._coerce_json_to_amendment(json_repr)
          if amendment is None:
              return None
          amendment_subtype = 'additions'
          # TODO: Look more deeply once we have other subtypes!
          first_ottid = amendment['TODO']
          last_ottid = amendment['TODO']
          return slugify('{s}-{f}-{l}'.format(s=amendment_subtype, f=first_ottid, l=last_ottid))
docs: Parse the JSON, return a slug in the form '{subtype}-{first ottid}-{last-ottid}'.