def decompose( i )
      values = @values.collect { |value| value.decompose i }
      self.class.new( *values ).demand
    end
def decompose( i )
      values = @values.collect { |value| value.decompose i }
      self.class.new( *values ).demand
    end
Decompose composite elements

 This method decomposes composite elements into array.

 @return [Node] Result of decomposition.