AT_DOCUMENT_START constant
UserScriptInjectionTime
const AT_DOCUMENT_START
NOTE for iOS: A constant to inject the script after the creation of the webpage’s document element, but before loading any other content.
NOTE for Android: A constant to try to inject the script as soon as the page starts loading.
Implementation
static const AT_DOCUMENT_START = UserScriptInjectionTime._internal(0, 0);