code: public static String join(final String delimiter, final Collection<?> elements)
  	{
  		if (elements == null || elements.isEmpty())
  		{
  			return "";
  		}
  		return join(delimiter, elements.toArray(new Object[elements.size()]));
  	}
docs: Same as {@link #join(String, Object...)} but with a {@link Collection} instead of an Array for the
  elements.
  
  @see #join(String, java.util.Collection)