Function walk_dependencies 

pub fn walk_dependencies(
    storage: &GameStorage,
    all_files: &[PathBuf],
    roots: &[PathBuf],
    ignored_extensions: &[&str],
) -> Result<Vec<PathBuf>>

Recursively find all game dependencies starting from known configuration files.

Roots:

• object_classes.txt
• board_types.txt
• player_types.txt
• *cnf.txt

From there, it parses these files to find references to other files (textures, models, other configs), and recursively resolves them.