instruction: Write Docker code for storage
output: ```bash
  $ docker pull ubuntu
  
  Using default tag: latest
  latest: Pulling from library/ubuntu
  e0a742c2abfd: Pull complete
  486cb8339a27: Pull complete
  dc6f0d824617: Pull complete
  4f7a5649a30e: Pull complete
  672363445ad2: Pull complete
  Digest: sha256:84c334414e2bfdcae99509a6add166bbb4fa4041dc3fa6af08046a66fed3005f
  Status: Downloaded newer image for ubuntu:latest
  ```