If result is null, set result be the result of resolving an - imports match given normalizedSpecifier, asURL, and - importMap's imports.
If result is null, set result be the result of resolving an + imports match given normalizedSpecifier, asURL, and + importMap's imports.
+At this point, if result is null, specifier wasn't remapped to anything by importMap, but it might have been able to be turned into a URL.
- -If result is null, set it to asURL.
If result is null, set it to asURL.
If result is not null, then: