isNonCanonicalScheme method
Returns whether the given URL scheme (without :
) should be considered
"non-canonical" for this importer.
An importer may not return a URL with a non-canonical scheme from canonicalize. In exchange, containingUrl is available within canonicalize for absolute URLs with non-canonical schemes so that the importer can resolve those URLs differently based on where they're loaded.
This must always return the same value for the same scheme
. It is
expected to be very efficient.
Implementation
FutureOr<bool> isNonCanonicalScheme(String scheme) => false;