<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def disable_all_breakpoints(cls):
 """ Disable all breakpoints and udate `active_breakpoint_flag`. """

        for bp in cls.breakpoints_by_number:
            if bp:  # breakpoint #0 exists and is always None
                bp.enabled = False
        cls.update_active_breakpoint_flag()
        return