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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_breakpoints(self, lineno):
 """Return the list of breakpoints set at lineno."""

        try:
            firstlineno, actual_lno = self.bdb_module.get_actual_bp(lineno)
        except BdbSourceError:
            return []
        if firstlineno not in self:
            return []
        code_bps = self[firstlineno]
        if actual_lno not in code_bps:
            return []
        return [bp for bp in sorted(code_bps[actual_lno],
                    key=attrgetter('number')) if bp.line == lineno]