def add_sequence(tag, options={})
      add(s = Sequence.new(tag, options))
      s
    end
def add_sequence(tag, options={})
      add(s = Sequence.new(tag, options))
      s
    end
Creates a Sequence with the given arguments and connects it to self.

 @param [String] tag a sequence tag
 @param [Hash] options any options used for creating the sequence (see Sequence.new documentation)