private static void decodeCells(Inspector cells, Tensor.Builder builder) {
        if (cells.type() == Type.ARRAY)
            cells.traverse((ArrayTraverser) (__, cell) -> decodeCell(cell, builder));
        else if (cells.type() == Type.OBJECT)
            cells.traverse((ObjectTraverser) (key, value) -> decodeSingleDimensionCell(key, value, builder));
        else
            throw new IllegalArgumentException("Excepted 'cells' to contain an array or object, not " + cells.type());
    }
Deserializes the given tensor from JSON format
vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java