private GTreeNode createRootNode(String projectName) {
		if (projectData == null) {
			return new NoProjectNode();
		}
		return new DomainFolderRootNode(projectName, projectData.getRootFolder(), projectData,
			filter);
	}
Create the root node for this data tree.
Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ProjectDataTreePanel.java