private JmespathExpression parseFlatten(JmespathExpression left) {
        int line = iterator.line();
        int column = iterator.column();
        JmespathExpression flatten = new FlattenExpression(left, left.getLine(), left.getColumn());
        JmespathExpression right = parseProjectionRhs(TokenType.STAR.lbp);
        return new ProjectionExpression(flatten, right, line, column);
    }
Tokens that can follow led tokens.
smithy-jmespath/src/main/java/software/amazon/smithy/jmespath/Parser.java