ModuleNotFoundError: No module named 'avalanche.benchmarks.generators'

#from avalanche.benchmarks.generators import nc_benchmark, ni_benchmark
ModuleNotFoundError: No module named 'avalanche.benchmarks.generators'

#from avalanche.training.strategies import Replay
ModuleNotFoundError: No module named 'avalanche.training.strategies'

All other packages are working for me except the above two! What would be the issue? please help!