docs: def deadends(self):
          """
          Get all CFGNodes that has an out-degree of 0
  
          :return: A list of CFGNode instances
          :rtype:  list
          """
          if self.graph is None:
              raise AngrCFGError('CFG hasn\'t been generated yet.')
  
          deadends = [i for i in self.graph if self.graph.out_degree(i) == 0]
  
          return deadends