code: def check_pseudo_package(path):
      
      if not os.path.isdir(path):
          raise Exception("Please make sure pseudo-package %s exists." % path)
      else:
          assets = os.listdir(path)
          if len(assets) == 0:
              raise Exception("Please make sure pseudo-package %s is populated." % path)
docs: Verifies that a fake subpackage path for assets (notebooks, svgs,
      pngs etc) both exists and is populated with files.