@CheckForNull
  public final V getOrDefault(@CheckForNull Object key, @CheckForNull V defaultValue) {
    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *

	if s3Err != ErrNone {
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(s3Err), r.URL)
		return
	}

	var targetAccount string

	// If listing is requested for a specific user (who is not the request
	// sender), check that the user has permissions.
	user := r.Form.Get("user")
	if user != "" && user != cred.AccessKey {
		if !globalIAMSys.IsAllowed(policy.Args{
			AccountName:     cred.AccessKey,

call site.
</p>

<p>
Given the function and calls
</p>
<pre>
func Greeting(prefix string, who ...string)
Greeting("nobody")
Greeting("hello:", "Joe", "Anna", "Eileen")
</pre>

<p>
within <code>Greeting</code>, <code>who</code> will have the value
<code>nil</code> in the first call, and
<code>[]string{"Joe", "Anna", "Eileen"}</code> in the second.
</p>