List<Expression> expandStarExpressions(List<? extends Expression> exprs, LogicalPlan child) {
            return flatMapToList(exprs, e -> {
                if (e instanceof Star) {
                    return ((Star) e).expand(child, resolver);
                }
                return Collections.singleton(e);
            });
        }
Foreach expression, expands the matching attribute.*'s in `child`'s input for the subtree
rooted at each expression.
indexr-query-opt/src/main/java/io/indexr/query/Analyzer.java