/**
 * There are various forms of results that are represented by this class:
 * <ol>
 * <li>success - in which case only the model field is set
 * <li>success with warnings - model field + non-error model problems
 * <li>error - no model, but diagnostics
 * <li>error - (partial) model and diagnostics
 * </ol>
 * Could encode these variants as subclasses, but kept in one for now
 *
 * @param <T> the model type
 */

   *
   * <ul>
   *   <li>When a {@code ListenableFuture} listener is registered to run under {@code
   *       directExecutor}, the listener can execute in any of three possible threads:
   *       <ol>
   *         <li>When a thread attaches a listener to a {@code ListenableFuture} that's already
   *             complete, the listener runs immediately in that thread.

				levels := strings.Split(loggerLevelString, ",")
				for _, ol := range levels {
					if !strings.Contains(ol, ":") && !strings.Contains(ol, "=") {
						level, ok := stringToLevel[ol]
						if ok {
							destLoggerLevels = map[string]Level{
								defaultLoggerName: level,
							}
						} else {
							return fmt.Errorf("unrecognized logging level: %v", ol)
						}
					} else {

				levels := strings.Split(loggerLevelString, ",")
				for _, ol := range levels {
					if !strings.Contains(ol, ":") && !strings.Contains(ol, "=") {
						level, ok := stringToLevel[ol]
						if ok {
							destLoggerLevels = map[string]Level{
								defaultLoggerName: level,
							}
						} else {
							return fmt.Errorf("unrecognized logging level: %v", ol)
						}
					} else {

Comments serve as program documentation. There are two forms:
</p>

<ol>
<li>
<i>Line comments</i> start with the character sequence <code>//</code>
and stop at the end of the line.
</li>
<li>
<i>General comments</i> start with the character sequence <code>/*</code>
and stop with the first subsequent character sequence <code>*/</code>.
</li>
</ol>

<p>

Comments serve as program documentation. There are two forms:
</p>

<ol>
<li>
<i>Line comments</i> start with the character sequence <code>//</code>
and stop at the end of the line.
</li>
<li>
<i>General comments</i> start with the character sequence <code>/*</code>
and stop with the first subsequent character sequence <code>*/</code>.
</li>
</ol>

<p>

 * As a result, it usually helps to read chained ordering expressions <i>backwards</i>. For example,
 * when {@code compare} is called on the above ordering:
 *
 * <ol>
 *   <li>First, if only one {@code Foo} is null, that null value is treated as <i>greater</i>
 *   <li>Next, non-null {@code Foo} values are passed to {@code getBarFunction} (we will be