code: public <T> T pick (Iterable<? extends T> iterable, T ifEmpty)
      {
          return pickPluck(iterable, ifEmpty, false);
      }
docs: Pick a random element from the specified Iterable, or return <code>ifEmpty</code>
  if it is empty.
  
  <p><b>Implementation note:</b> optimized implementations are used if the Iterable
  is a List or Collection. Otherwise, it behaves as if calling {@link #pick(Iterator, Object)}
  with the Iterable's Iterator.
  
  @throws NullPointerException if the iterable is null.