docs: def remove_total_size(apps, schema_editor):
      """Remove ``total_size`` field from all file/dir-type outputs."""
      Data = apps.get_model('flow', 'Data')
      for data in Data.objects.all():
          for field_schema, fields in iterate_fields(data.output, data.process.output_schema):
              name = field_schema['name']
              value = fields[name]
              if 'type' in field_schema:
                  if field_schema['type'].startswith('basic:file:'):
                      del value['total_size']
                  elif field_schema['type'].startswith('list:basic:file:'):
                      for obj in value:
                          del obj['total_size']
                  elif field_schema['type'].startswith('basic:dir:'):
                      del value['total_size']
                  elif field_schema['type'].startswith('list:basic:dir:'):
                      for obj in value:
                          del obj['total_size']
          data.save()