About keras_contrib.backend

[yuanyuan1993]

install keras_contrib by:
pip install git+https://www.github.com/keras-team/keras-contrib.git

and run:
import keras_contrib.backend as KC
KC.backend()

But error :
Traceback (most recent call last):
File "", line 1, in
AttributeError: 'module' object has no attribute 'backend'\\

What should I do？ Thank you.