<p><code>String "eternal", "long", "moderate", or "short"
with the default derived from a test's size attribute)</code></p>

<p>
How long the test is normally expected to run before returning.
</p>

<p>
While a test's size attribute controls resource estimation, a test's
timeout may be set independently.  If not explicitly specified, the
timeout is based on the test's size (with "small" &rArr; "short",
"medium" &rArr; "moderate", etc...). By default, "short" means 1 minute,
"moderate" 5 minutes, "long" 15 minutes, and "eternal" 60 minutes (this
can be overridden with --test_timeout, e.g. for running under certain
configurations which are known to be slow).
</p>