URIUtils propose a SCHEMAURI_CHECKER. But if the URI begins with "jar:file:", the argument.getPath() will return a null value then we will get a null pointer exception. ``` private static final ArgumentChecker<URI> SCHEMAURI_CHECKER = new ArgumentChecker<URI>() { @Override public void check(final URI argument) { BUNDLE.checkArgumentPrintf(argument.isAbsolute(), "uriChecks.notAbsolute", argument); final JsonRef ref = JsonRef.fromURI(argument); BUNDLE.checkArgumentPrintf(ref.isAbsolute(), "uriChecks.notAbsoluteRef", argument); BUNDLE.checkArgumentPrintf(!argument.getPath().endsWith("/"), "uriChecks.endingSlash", argument); } }; ```