code: def disk_check_size(ctx, param, value):
      
      if value:
          # if we've got a prefix
          if isinstance(value, tuple):
              val = value[1]
          else:
              val = value
          if val % 1024:
              raise click.ClickException('Size must be a multiple of 1024.')
      return value
docs: Validation callback for disk size parameter.