static CharSequence expectAndSkipAbsoluteShapeId(IdlInternalTokenizer tokenizer) {
        int startPosition = tokenizer.getCurrentTokenStart();
        int endOffset = skipAbsoluteShapeId(tokenizer);
        return sliceFrom(tokenizer, startPosition, endOffset);
    }
Expects that the tokenizer is on an absolute shape ID, skips over it, and returns a borrowed slice of the
shape ID.

@param tokenizer Tokenizer to consume and advance.
@return Returns the borrowed shape ID.
smithy-model/src/main/java/software/amazon/smithy/model/loader/IdlShapeIdParser.java