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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_input_var_names(self):
 """Return a list of variables names that can be set as input. Returns ------- var_names : list[str] A list of variable names that can be set from the outside """

        in_vars = copy.copy(self.input_vars)
        for idx, var in enumerate(in_vars):
            if self._map_in_out(var) is not None:
                in_vars[idx] = self._map_in_out(var)
        return in_vars