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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 in_(self, *objs):
 """ Create a condition """

        if not objs:
            return self.table.c[self.fielda]!=self.table.c[self.fielda]
        else:
            keys = get_objs_columns(objs, self.reference_fieldname)
            sub_query = select([self.table.c[self.fielda]], (self.table.c[self.fieldb] == self.reference_class.c[self.reference_fieldname]) & (self.table.c[self.fieldb].in_(keys)))
            condition = self.model_class.c[self.reversed_fieldname].in_(sub_query)
            return condition