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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 to_timestamp(self, data):
 """Transform a datetime series into linux epoch. Args: data(pandas.DataFrame):
 DataFrame containins a column named as `self.col_name`. Returns: pandas.Series """

        result = pd.Series(index=data.index)
        _slice = ~data[self.col_name].isnull()

        result[_slice] = data[_slice][self.col_name].astype('int64')
        return result