`RUST_TEST_TIME_DOCTEST` environment variables.
Expected format of environment variable is `VARIABLE=WARN_TIME,CRITICAL_TIME`.
+ Durations must be specified in milliseconds, e.g. `500,2000` means that the warn time
+ is 0.5 seconds, and the critical time is 2 seconds.
Not available for --format=terse",
"plain|colored",