private void consumeNumber() {
            consumeNumber(builder.type().valueType(),
                          f -> builder.cell(f, indexes),
                          d -> builder.cell(d, indexes));
        }
Parses unbound tensor short forms - e.g. tensor(x[],y[]):[[1,2,3],[4,5,6]]
vespajlib/src/main/java/com/yahoo/tensor/TensorParser.java