code: def _shift_field_positions_global(record, start, delta=1):
      
      if not delta:
          return
  
      for tag, fields in record.items():
          newfields = []
          for field in fields:
              if field[4] < start:
                  newfields.append(field)
              else:
                  # Increment the global field position by delta.
                  newfields.append(tuple(list(field[:4]) + [field[4] + delta]))
          record[tag] = newfields
docs: Shift all global field positions.
  
      Shift all global field positions with global field positions
      higher or equal to 'start' from the value 'delta'.