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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 set_data_length(self, length):
        # type: (int) -> None
        '''
        A method to set the length of data for this El Torito Entry.

        Parameters:
         length - The new length for the El Torito Entry.
        Returns:
         Nothing.
        '''
        if not self._initialized:
            raise pycdlibexception.PyCdlibInternalError('El Torito Entry not initialized')
        self.sector_count = utils.ceiling_div(length, 512)