code: def timestamp_compare(instance):
      
      compares = [('modified', 'ge', 'created')]
      additional_compares = enums.TIMESTAMP_COMPARE.get(instance.get('type', ''), [])
      compares.extend(additional_compares)
  
      for first, op, second in compares:
          comp = getattr(operator, op)
          comp_str = get_comparison_string(op)
  
          if first in instance and second in instance and \
                  not comp(instance[first], instance[second]):
              msg = "'%s' (%s) must be %s '%s' (%s)"
              yield JSONError(msg % (first, instance[first], comp_str, second, instance[second]),
                              instance['id'])
docs: Ensure timestamp properties with a comparison requirement are valid.
  
      E.g. `modified` must be later or equal to `created`.