tests: replace imported module to avoid check-code.py error This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts.

tests: bulk change to avoid "unneeded trailing ',' ..." error of check-code.py This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. "trailing ','" at the end of command option list in the code fragment of test-bundle2-format.t is still left as it is, in order to follow the style of command definitions in Mercurial core.

tests: define class in modern style to avoid check-code.py error This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts.

tests: use NO_CHECK_EOF as heredoc limit mark to omit checking code fragments This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. "primes.py" embedded in test-highlight.t causes an error of check-commit.py below: don't use .next(), use next(...) But changing embedded primes.py is painful, because it is committed in test script, and affects hash IDs. On the other hand, primes.py itself is never executed in test script. Therefore, this patch uses NO_CHECK_EOF as heredoc limit mark in order to omit any checking on this code fragments.