protected static void parseOptionalForResource(CapturingTokenizer tokenizer) {
        optionalSpaces(tokenizer);
        if (tokenizer.isCurrentLexeme("for")) {
            FOR_RESOURCE.parse(tokenizer);
        }
    }
The innermost node of the token tree that contains an actual token returned from {@link IdlTokenizer}.
smithy-syntax/src/main/java/software/amazon/smithy/syntax/TreeType.java