# Making a graphics array with different numbers of plots in each row

I'm trying to create a graphics array with one plot in the first row and three in the second. Here's a minimal example:

```
p0 = plot(x)
p1 = plot(x^2)
p2 = plot(x^3)
g = graphics_array([[p0], [p1, p2]])
g.show()
```

When executing this, I get each plot separately and then an error message reading, "TypeError: array (=[[], [, ]]) must be a list of lists of Graphics objects". What am I doing wrong? How is what I have not a list of lists of Graphics objects?