How to use the zarr.empty_like function in zarr

def verify_round_trip(self, source):
        """
        Verify that we can round trip the specified mapping of arrays
        using the buffered item writer.
        """
        # Create a set of empty arrays like the originals.
        dest = {}
        num_rows = -1
        for key, array in source.items():
            dest[key] = zarr.empty_like(array)
            if num_rows == -1:
                num_rows = array.shape[0]
            assert num_rows == array.shape[0]
        assert num_rows != -1
        writer = formats.BufferedItemWriter(dest, num_threads=self.num_threads)
        for j in range(num_rows):
            row = {key: array[j] for key, array in source.items()}
            writer.add(**row)
        writer.flush()

        for key, source_array in source.items():
            dest_array = dest[key]
            if source_array.dtype.str == "|O":
                # Object arrays have to be treated differently.
                self.assertTrue(source_array.shape == dest_array.shape)
                for a, b in zip(source_array, dest_array):