class Aws::Xml::Parser

def set_default_engine
  [:ox, :oga, :libxml, :nokogiri, :rexml].each do |name|
    @engine ||= try_load_engine(name)
  end
  unless @engine
    raise 'Unable to find a compatible xml library. ' \
    'Ensure that you have installed or added to your Gemfile one of ' \
    'ox, oga, libxml, nokogiri or rexml'
  end
end