as added by 'dream' in late 2011. Testing couldn't have happened,
   as they don't work and can't ever work as designed.
   Channels must have underlying file descriptors unless you implement
   your own Selector and that would probably require JNI.
   See http://zzz.i2p/topics/1229 for details.
   Also http://stackoverflow.com/questions/911780/how-do-i-define-my-own-selectablechannel