public String toJson(JsonFormat.EncodeOptions tensorOptions) {
        return writeJson(tensorOptions, new StringBuilder()).toString();
    }
Returns the fields of this as an inspector, where tensors are represented as binary data
which can be decoded using
<code>com.yahoo.tensor.serialization.TypedBinaryFormat.decode(Optional.empty(), GrowableByteBuffer.wrap(featureValue.asData()))</code>
container-search/src/main/java/com/yahoo/search/result/FeatureData.java