def parse(node)
      node.xpath('*').each do |node_child|
        case node_child.name
        when 'blip'
          @blip = Blip.new(parent: self).parse(node_child)
        when 'stretch'
          @stretch = Stretch.new(parent: self).parse(node_child)
        end
      end
      self
    end
def parse(node)
      node.xpath('*').each do |node_child|
        case node_child.name
        when 'blip'
          @blip = Blip.new(parent: self).parse(node_child)
        when 'stretch'
          @stretch = Stretch.new(parent: self).parse(node_child)
        end
      end
      self
    end
Parse BlipFill object
 @param node [Nokogiri::XML:Element] node to parse
 @return [BlipFill] result of parsing