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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 __read_source_file(self):
 """ Reads the file with the source of the stored routine. """

        with open(self._source_filename, 'r', encoding=self._routine_file_encoding) as file:
            self._routine_source_code = file.read()

        self._routine_source_code_lines = self._routine_source_code.split("\n")