# File lib/more/facets/random.rb, line 381
    def at_rand!( separator=// )
      #separator = self.class.patterns( separator )
      a = self.shatter( separator )
      w = []; a.each_with_index { |s,i| i % 2 == 0 ? w << s : w.last << s }
      i = Random.number(w.size)
      r = w.delete_at( i )
      self.replace( w.join('') )
      return r
    end