code: def add_institution(self, institution, start_date=None, end_date=None, rank=None, record=None, curated=False, current=False):
          
          new_institution = {}
          new_institution['institution'] = institution
          if start_date:
              new_institution['start_date'] = normalize_date(start_date)
          if end_date:
              new_institution['end_date'] = normalize_date(end_date)
          if rank:
              new_institution['rank'] = rank
          if record:
              new_institution['record'] = record
          new_institution['curated_relation'] = curated
          new_institution['current'] = current
          self._append_to('positions', new_institution)
          self.obj['positions'].sort(key=self._get_institution_priority_tuple, reverse=True)
docs: Add an institution where the person works/worked.
  
          Args:
              :param institution: name of the institution.
              :type institution: string
  
              :param start_date: the date when the person joined the institution, in any format.
              :type start_date: string
  
              :param end_date: the date when the person left the institution, in any format.
              :type end_date: string
  
              :param rank: the rank of academic position of the person inside the institution.
              :type rank: string
  
              :param record: URI for the institution record.
              :type record: string
  
              :param curated: if the institution has been curated i.e. has been verified.
              :type curated: boolean
  
              :param current: if the person is currently associated with this institution.
              :type current: boolean