default List<Cell> smallest() {
        List<Cell> cells = new ArrayList<>(1);
        double minValue = Double.MAX_VALUE;
        for (Iterator<Cell> i = cellIterator(); i.hasNext(); ) {
            Cell cell = i.next();
            if (cell.getValue() < minValue) {
                cells.clear();
                cells.add(cell.detach());
                minValue = cell.getDoubleValue();
            }
            else if (cell.getValue() == minValue) {
                cells.add(cell.detach());
            }
        }
        return cells;
    }
Returns the cell(s) of this tensor having the lowest value
vespajlib/src/main/java/com/yahoo/tensor/Tensor.java