protected static void parseSharedStructureBodyWithinInline(CapturingTokenizer tokenizer) {
        parseOptionalForResource(tokenizer);
        parseOptionalMixins(tokenizer);

        optionalWs(tokenizer);
        SHAPE_MEMBERS.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