BrowserVersionOwn?TypeAs String
Chrome81.0.4044???
Chrome86.0.4240ownfunctionfunction IdleDeadline() { [native code] }
Chrome88.0.4301???
Edge86.0.622ownfunctionfunction IdleDeadline() { [native code] }
Edge87.0.651???
Edge87.0.658ownfunctionfunction IdleDeadline() { [native code] }
Firefox68.0.0???
Firefox79.0.0ownfunctionfunction IdleDeadline() { [native code] }
HeadlessChrome81.0.4044ownfunctionfunction IdleDeadline() { [native code] }
IE10.0.0???
Safari10.1.2???

PropertiesChromeEdgeFirefoxHeadlessChromeIESafari
length 86.0.4240 86.0.622 79.0.0 81.0.4044??
prototype 86.0.4240 86.0.622 79.0.0 81.0.4044??