Exploring Graphs with Elixir: Missing directories (p 100, 105)

Exploring Graphs with Elixir by @tonyhammond

p.100 – Ch 3 > Storing Graphs in the Graph Store > Listing
shows

“iex>​​ ​​list_graphs​
​ 	[..., "default.dot", "IMAGES", ...]”

but (to my recollection) we have not defined this directory yet, either manually or automatically through the shell command in:
p.68 – Ch 2 > Building a Graph Store > Creating a Storage area

I see a reference to this “images” directory later, as a module attribute in NativeGraph.Format
So I manually created it.

Then in
p.105 – Ch 3 > Visualizing Graphs > Rendering with Graph Viz
while creating the water molecule graph, we’re given:

“iex>​​ ​​with​​ ​​{:ok,​​ ​​dot}​​ ​​=​​ ​​Graph.to_dot(g)​​ ​​do​
​ 	​...>​​ ​​write_graph(dot,​​ ​​"dot/h2o.dot"​​)​
​ 	​...>​​ ​​end”

When trying this, I get a File error since the “dot” directory is unavailable. Not sure what I’m missing here, or if the directory is supposed to be automatically created?
I manually created a “dot” directory to make the code work as shown and tested in later pages.