A JSON MethodChannel for navigation.
The following incoming methods are defined for this channel (registered using MethodChannel.setMethodCallHandler):
popRoute, which is called when the system wants the current route to be removed (e.g. if the user hits a system-level back button).
pushRoute, which is called with a single string argument when the operating system instructs the application to open a particular page.
static const MethodChannel navigation = MethodChannel( 'flutter/navigation', JSONMethodCodec(), )