Show hidden cells in Pluto

How can I show hidden cells in Pluto.jl?
Specifically, if you open this notebook in Pluto, you will not see all the other using statements after

using Plots; default(fontfamily="Computer Modern", framestyle=:box) # LaTex-style

but they are present in the plain .jl file, and are executed when Pluto opens it. Is it possible to see that within Pluto?

There is a little eye-symbol next to each Pluto cell on the left side. When you click it, the source code of the cell is shown/hidden.

It was not that. I think it was that the cells are present, but they are not evaluated in the order the show up in the notebook.

The evaluation order of Pluto cells is determined automatically by their dependencies. It is in general independent of the cell ordering shown in the notebook.
The cell order in the notebook.jl file corresponds to the evaluation order (not the one shown in the notebook) so that the .jl file is executable stand-alone (without Pluto).

I see. But if you execute that jl file in Julia, not Pluto, you will get an error, because at the time the struct GridWorldParameters is defined, the struct State is not defined, no?