code: def read_single_xso(src, type_):
      
  
      result = None
  
      def cb(instance):
          nonlocal result
          result = instance
  
      read_xso(src, {type_: cb})
  
      return result
docs: Read a single :class:`~.XSO` of the given `type_` from the binary file-like
      input `src` and return the instance.