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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 reg_concrete(self, *args, **kwargs):
 """ Returns the contents of a register but, if that register is symbolic, raises a SimValueError. """

        e = self.registers.load(*args, **kwargs)
        if self.solver.symbolic(e):
            raise SimValueError("target of reg_concrete is symbolic!")
        return self.solver.eval(e)