Address review comment: More accurate explanation.
Address review comment: Less complicated implementation.
Address review comment: link to issue for SSH replacement.
Address review comment: JP hates commas.
Address review comment: Consistent import style.
Address review comment: Better error handling will be follow-up issue.
Address review comment: Explain security is not a concern at this phase, and this particular issue will be gone by the time we care.
Address review comment: Make copy() a function instead of a method.
Address review comment: Replace tuple with a class.
Address review comment: More useful tests of exceptions aborting writes.
Address review comment: Specify interface better.
Address review comment: Document positional arguments.
Address review comment: Delegation.
Address review comment: Address the looming comma shortage.
Try to make flake8 happier.