How to call a custom module (loader) in graphgym ?

[OscarRoussel]

I'm trying to create my own loader for a data I constructed in PyG to give it to graph gym to run experiments and I'm running in difficulties finding documentation that explains how to actually call the created module.

My current use case is creating a specific loader to load a custom PyG InMemoryDataset into graphgym and running experiments on that dataset.
But to understand how the process work I'm looking at the graphgym/custom_graphgym/loader/example.py file and can't seem to understand where in graphgym this example loader can be called.

Many thanks for any help.