PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 41.0.2272? 12.0.0???? 3.0.0 6.0.0
prototype 41.0.2272? 12.0.0???? 3.0.0 6.0.0
toString 47.0.2526????????