def parse(node)
      node.attributes.each do |key, value|
        case key
        when 'type'
          @unit = value.value.to_sym
        when 'w', 'val'
          @value = value.value.to_f
        end
      end
      self
    end
def parse(node)
      node.attributes.each do |key, value|
        case key
        when 'type'
          @unit = value.value.to_sym
        when 'w', 'val'
          @value = value.value.to_f
        end
      end
      self
    end
Parse OoxmlSize
 @param [Nokogiri::XML:Node] node with OoxmlSize
 @return [OoxmlSize] result of parsing