Example: web.concurrent_end

In the following example, the concurrent_end function marks the end of a concurrent group.

web.concurrent_start(null);
     web.add_header(...);
     web.url(..., "URL=http://...url1", new String[]{ ...});
     web.add_header(...);
     web.add_header(...);
     web.url(..., "URL=http://...url2", new String[]{ ...});
...
web.concurrent_end(null);