def clear(self):
        """ Clear a breakpoint by removing it from all lists.
        """
        del IKBreakpoint.breakpoints_by_file_and_line[self.file_name, self.line_number]
        IKBreakpoint.breakpoints_by_number[self.number] = None
        IKBreakpoint.breakpoints_files[self.file_name].remove(self.line_number)
        if len(IKBreakpoint.breakpoints_files[self.file_name]) == 0:
            del IKBreakpoint.breakpoints_files[self.file_name]
        IKBreakpoint.update_active_breakpoint_flag()
Clear a breakpoint by removing it from all lists.