src/vs/workbench/browser/parts/editor/editorPane.ts/EditorMemento/loadEditorState
class EditorMemento:	loadEditorState(group: IEditorGroup, resourceOrEditor: URI | EditorInput): T | undefined {
		const resource = this.doGetResource(resourceOrEditor);
		if (!resource || !group) {
			return; // we are not in a good state to load any state for a resource
		}

		const cache = this.doLoad();

		const mementosForResource = cache.get(resource.toString());
		if (mementosForResource) {
			let mementoForResourceAndGroup = mementosForResource[group.id];

			// Return state for group if present
			if (mementoForResourceAndGroup) {
				return mementoForResourceAndGroup;
			}

			// Return most recent state based on settings otherwise
			if (this.shareEditorState) {
				return mementosForResource[EditorMemento.SHARED_EDITOR_STATE];
			}
		}

		return undefined;
	}