@Override
    public String toString() {
        return "field " + getName() + " type tensor";
    }
A tensor field. Tensors are encoded as a data field where the data (following the length)
is encoded in a tensor binary format defined by com.yahoo.tensor.serialization.TypedBinaryFormat

@author bratseth
container-search/src/main/java/com/yahoo/prelude/fastsearch/TensorField.java