~$ docker volume prune
WARNING! This will remove anonymous local volumes not used by at  
least one container.
Are you sure you want to continue? [y/N] y
Deleted Volumes:
56c25d5a7cce0682340b55734cf8620342f7c269c59f8ca1bac00bdd595f9983
baf78a0e9901c2d97e612379783ce19b3d855dda31e05e75b37f9227618986b0
e2145c19bcb5d905b466ec117fb1e28a24e4d6c4e63a04f03c824c401d9ae8d4
{...}
Total reclaimed space: 3.535GB
