default IdlToken expect(IdlToken... tokens) {
        IdlToken currentTokenType = getCurrentToken();

        for (IdlToken token : tokens) {
            if (currentTokenType == token) {
                return token;
            }
        }

        throw LoaderUtils.idlSyntaxError(LoaderUtils.idlExpectMessage(this, tokens), getCurrentTokenLocation());
    }
Assert that the current token is one of {@code tokens}.

<p>The tokenizer is not advanced after validating the current token.</p>

@param tokens Assert that the current token is one of these tokens.
@return Returns the current token.
@throws ModelSyntaxException if the current token is unexpected.
smithy-model/src/main/java/software/amazon/smithy/model/loader/IdlTokenizer.java