private static void decodeCell(Inspector cell, Tensor.Builder builder) {
        TensorAddress address = decodeAddress(cell.field("address"), builder.type());

        Inspector value = cell.field("value");
        if (value.valid()) {
            builder.cell(address, decodeNumeric(value));
        } else {
            throw new IllegalArgumentException("Excepted a cell to contain a numeric value called 'value'");
        }
    }
Deserializes the given tensor from JSON format
vespajlib/src/main/java/com/yahoo/tensor/serialization/JsonFormat.java