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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 drop_not_null(self, model, *names):
 """Drop not null."""

        for name in names:
            field = model._meta.fields[name]
            field.null = True
            self.ops.append(self.migrator.drop_not_null(model._meta.table_name, field.column_name))
        return model