How to use the pyedflib._extensions._pyedflib.blockwrite_physical_samples function in pyEDFlib

data_vec belonging to one signal. The size must be the samplefrequency of the signal.

        Notes
        -----
        buf must be filled with samples from all signals, starting with signal 0, 1, 2, etc.
        one block equals one second
        The physical samples will be converted to digital samples using the
        values of physical maximum, physical minimum, digital maximum and digital minimum
        The number of samples written is equal to the sum of the samplefrequencies of all signals
        Size of buf should be equal to or bigger than sizeof(double) multiplied by the sum of the samplefrequencies of all signals
        Returns 0 on success, otherwise -1

        All parameters must be already written into the bdf/edf-file.
        """
        return blockwrite_physical_samples(self.handle, data)