class_docstr: This class represents a directed graph using adjacency lists
class_docstr_tok: ["This","class","represents","a","directed","graph","using","adjacency","lists"]
docstr: A recursive DFS traversal function that finds
  all reachable vertices for source
docstr_tok: ["A","recursive","DFS","traversal","function","that","finds","all","reachable","vertices","for","source"]
code: def dfs_util(self, source, target):
      """
      A recursive DFS traversal function that finds
      all reachable vertices for source
      """
  
      # Mark reachability from source to target as true.
      self.closure[source][target] = 1
  
      # Find all the vertices reachable through target
      for adjacent in self.graph[target]:
          if self.closure[source][adjacent] == 0:
              self.dfs_util(source, adjacent)
  
label_desc: Use image node_id 3 for calling the Graph obj's underlying member method code with example usage: obj.dfs_util(source, target) without return types