Save two images into 1 tar file

I'm attempting to save two images into one file to mirror functionality offered by the docker save command. The code shown below only saves the first image in the file. Am I using improper syntax or is this functionality not supported?

f = open('test.tar', 'wb')

for chunk in imageOne.save(named=True):
    print("writing chunk")
    f.write(chunk)

for chunk in imageTwo.save(named=True):
    print("writing chunk")
    f.write(chunk)

f.close()

docker==4.1.0
docker-pycreds==0.4.0
Python 2.7.16
Client: Docker Engine - Community
 Version:           19.03.5
 API version:       1.40
 Go version:        go1.12.12
 Git commit:        633a0ea
 Built:             Wed Nov 13 07:22:34 2019
 OS/Arch:           darwin/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.5
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.12
  Git commit:       633a0ea
  Built:            Wed Nov 13 07:29:19 2019
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.2.10
  GitCommit:        b34a5c8af56e510852c35414db4c1f4fa6172339
 runc:
  Version:          1.0.0-rc8+dev
  GitCommit:        3e425f80a8c931f88e6d94a8c831b9d5aa481657
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

Start by reading the image.save(named=True) entry point and the Docker Engine save behavior described in the issue. Compare the tar stream returned for each image with the format produced by docker save. Done means confirming whether multiple images are supported, documenting the supported usage, or adding coverage for the intended behavior.