private TensorType decodeType(GrowableByteBuffer buffer) {
        int numDimensions = buffer.getInt1_4Bytes();
        TensorType.Builder builder = new TensorType.Builder(serializationValueType);
        for (int i = 0; i < numDimensions; ++i)
            builder.mapped(buffer.getUtf8String());
        return builder.build();
    }
Implementation of a sparse binary format for a tensor on the form:

Sorted dimensions = num_dimensions [dimension_str_len dimension_str_bytes]*
Cells = num_cells [label_1_str_len label_1_str_bytes ... label_N_str_len label_N_str_bytes cell_value]*

Note that the dimensions are sorted and the tensor address labels are given in the same sorted order.
Unspecified labels are encoded as the empty string "".

@author geirst
vespajlib/src/main/java/com/yahoo/tensor/serialization/SparseBinaryFormat.java