class_docstr: A simple graph class
  
      
code: def all_paths(self, graph, start, end=None, path=None):
      path = path or []
      path = path + [start]
      if start == end or graph[start] == {}:
          return [path]
      if start not in graph:
          return []
      paths = []
      for node in graph[start]:
          if node not in path:
              newpaths = self.all_paths(graph, node, end, path)
              for newpath in newpaths:
                  paths.append(newpath)
      return paths
  
file_path: dipy/dipy/core/graph.py
label_desc: Use image node_id 10 for calling the Graph obj's underlying member method code with example usage: obj.all_paths(graph, start, end, path) and returns: paths, list, list