code: def _represent_fold(fold_location, fold_ir_blocks):
      
      start_let_template = u'$%(mark_name)s = %(base_location)s'
      traverse_edge_template = u'.%(direction)s("%(edge_name)s")'
      base_template = start_let_template + traverse_edge_template
      edge_direction, edge_name = fold_location.get_first_folded_edge()
      mark_name, _ = fold_location.get_location_name()
      base_location_name, _ = fold_location.base_location.get_location_name()
  
      validate_safe_string(mark_name)
      validate_safe_string(base_location_name)
      validate_safe_string(edge_direction)
      validate_safe_string(edge_name)
  
      template_data = {
          'mark_name': mark_name,
          'base_location': base_location_name,
          'direction': edge_direction,
          'edge_name': edge_name,
      }
      final_string = base_template % template_data
  
      for block in fold_ir_blocks:
          if isinstance(block, Filter):
              final_string += u'[' + block.predicate.to_match() + u']'
          elif isinstance(block, Traverse):
              template_data = {
                  'direction': block.direction,
                  'edge_name': block.edge_name,
              }
              final_string += traverse_edge_template % template_data
          elif isinstance(block, MarkLocation):
              # MarkLocation blocks inside a fold do not result in any MATCH output.
              pass
          else:
              raise AssertionError(u'Found an unexpected IR block in the folded IR blocks: '
                                   u'{} {} {}'.format(type(block), block, fold_ir_blocks))
  
      # Workaround for OrientDB's inconsistent return type when filtering a list.
      # https://github.com/orientechnologies/orientdb/issues/7811
      final_string += '.asList()'
  
      return final_string
docs: Emit a LET clause corresponding to the IR blocks for a @fold scope.