private GhidraFolderData createFolderData(String folderName) throws IOException {
		synchronized (fileSystem) {
			GhidraFolderData parentData =
				parent == null ? projectData.getRootFolderData() : createFolderData();
			GhidraFolderData folderData = parentData.getFolderData(folderName, false);
			if (folderData == null) {
				try {
					folderData = parentData.createFolder(folderName);
				}
				catch (InvalidNameException e) {
					throw new IOException(e);
				}
			}
			return folderData;
		}
	}
Create folder hierarchy in local filesystem if it does not already exist
@param folderName
@return folder data
@throws IOException error while creating folder
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFolder.java