e programmer
 asked an injector to create a <code>StopwatchWidget</code> instance:

 <pre>   /** GUI for a Stopwatch &#42;/
   class StopwatchWidget {
     &#64;Inject StopwatchWidget(Stopwatch sw) { ... }
     ...
   }</pre>

 <p>The injector might:
 <ol>
   <li>Find a <code>TimeSource</code>
   <li>Construct a <code>Stopwatch</code> with the <code>TimeSource</code>
   <li>Construct a <code>StopwatchWidget</code> with the <code>Stopwatch</code>
 </ol>

 <p>This leaves the programmer's code clean, flexible,