def parse(node)
      list = []
      node.xpath('*').each do |node_child|
        case node_child.name
        when 'AlternateContent'
          list << AlternateContent.new(parent: self).parse(node_child)
        end
      end
      list
    end
def parse(node)
      list = []
      node.xpath('*').each do |node_child|
        case node_child.name
        when 'AlternateContent'
          list << AlternateContent.new(parent: self).parse(node_child)
        end
      end
      list
    end
Parse OleObjects object
 @param node [Nokogiri::XML:Element] node to parse
 @return [Array] list of OleObjects