code: def get_all_predecessors(self, cfgnode):
          
          s = set()
          for child, parent in networkx.dfs_predecessors(self.graph, cfgnode).items():
              s.add(child)
              s.add(parent)
          return list(s)
docs: Get all predecessors of a specific node on the control flow graph.
  
          :param CFGNode cfgnode: The CFGNode object
          :return: A list of predecessors in the CFG
          :rtype: list