private void encodeSparseDimensions(GrowableByteBuffer buffer, MixedTensor tensor) {
        List<TensorType.Dimension> sparseDimensions = tensor.type().dimensions().stream().filter(d -> !d.isIndexed()).toList();
        buffer.putInt1_4Bytes(sparseDimensions.size());
        for (TensorType.Dimension dimension : sparseDimensions) {
            buffer.putUtf8String(dimension.name());
        }
    }
Implementation of a mixed binary format for a tensor.
See eval/src/vespa/eval/tensor/serialization/format.txt for format.

@author lesters
vespajlib/src/main/java/com/yahoo/tensor/serialization/MixedBinaryFormat.java