Adding a <graphicdata> category to an existing def with a patch

[Jackdawson]

After trying to add subcategories like <texpath> to a def with no graphicData category I realized that adding those categories is something I haven't done until now

I tried adding it like this but I'm guessing that this does nothing. What is the correct way to patch <graphicdata> into a def?

<li Class="PatchOperationAdd">
                  <xpath>*/ThingDef[defName = "ExampleDef"]</xpath>
                     <value>
                    <graphicData>
                  </value>
             </li>