<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _set_add_options(cls, checked_codes, options):
 """Set `checked_codes` by the `add_ignore` or `add_select` options."""

        checked_codes |= cls._expand_error_codes(options.add_select)
        checked_codes -= cls._expand_error_codes(options.add_ignore)