The `graph` directive supports the following parameters:
- `src` - The graphviz source to render.
+* `file` - A file in the wiki containing the graphviz source.
- `type` - The type of graph to render: `graph` or `digraph`. Defaults to
`digraph`.
- `prog` - The graphviz program to render with: `dot`, `neato`, `fdp`, `twopi`,