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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 _clean_data(self, str_value, file_data, obj_value):
 """This overwrite is neccesary for work with multivalues"""

        str_value = str_value or None
        obj_value = obj_value or None
        return (str_value, None, obj_value)