maximum_spanning_tree networkx has no attribute

Question

I am trying to find maximum spanning tree of a network using networkx python module. According to documentation specified[link below], nx.maximum_spanning_tree(G) should do this work. But i am getting error

  File "air_traffic_network_base.py", line 65, in <module>
    max_spanning_tree = nx.maximum_spanning_tree(net)
AttributeError: 'module' object has no attribute 'maximum_spanning_tree'

Here is the code snippet:

net = nx.read_weighted_edgelist(graph_file)
min_spanning_tree = nx.minimum_spanning_tree(net) #no error
max_spanning_tree = nx.maximum_spanning_tree(net) #error here

Documentation: http://networkx.readthedocs.org/en/latest/reference/generated/networkx.algorithms.tree.mst.maximum_spanning_tree.html

Networkx version (nx.__version__):
1.10

I believe i am using latest networkx python module.(minimum_spanning_tree function call works without any error).

Please help.