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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 is_code_unit(self):
 """Is this a "code" unit? Returns ------- True if the unit consists of atom units that being with "code". False otherwise """

        for atom in self.expr.atoms():
            if not (str(atom).startswith("code") or atom.is_Number):
                return False
        return True