def load(*file_names)
            file_names.flatten.each do |file_name|
                xml = File.open(file_name, 'r') do |file|
                    Nokogiri::XML(file) do |config|
                        if @pretty then
                            config.default_xml.noblanks
                        end
                    end
                end
                @documents << Document.new(file_name, xml)
            end
        end
def load(*file_names)
            file_names.flatten.each do |file_name|
                xml = File.open(file_name, 'r') do |file|
                    Nokogiri::XML(file) do |config|
                        if @pretty then
                            config.default_xml.noblanks
                        end
                    end
                end
                @documents << Document.new(file_name, xml)
            end
        end
Intialize a new mixml tool
 Load XML files

 @param file_names [Array] Names of the XML files to load
 @return [void]