roll_cagr not working

[Jacques2101]

I am trying to do:

from empyrical import  roll_beta, roll_alpha, roll_sharpe_ratio, roll_annual_volatility, roll_cagr

but get an error message whereas the function seems to exists. I don't know why (the others functions are ok)

ImportError: cannot import name 'roll_cagr' from 'empyrical' 

thx for your help.