PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 27.0.1453? 17.0.0 50.0.0??? 3.0.0 9.0.0
prototype 27.0.1453? 13.0.0 50.0.0??? 3.0.0 9.0.0
prototype?? 15.15063.0??????