AttributeError: 'module' object has no attribute 'graph'

[boonflies]

I have pygraph installed in my pc but still when I run planner_example.py, I get the error,

17:06:49 - DEBUG: ATTEMPT 1.
17:06:49 - DEBUG: build_rrt started
Traceback (most recent call last):
File "planner_example.py", line 27, in
tree = rrt.build_rrt()
File "/home/boon/Packages/RRT/rrt-planner-master/trunk/rrt.py", line 23, in build_rrt
g = pygraph.graph()
AttributeError: 'module' object has no attribute 'graph'