presto-main/src/main/java/io/prestosql/sql/planner/ExpressionSymbolInliner.java/ExpressionSymbolInliner/rewriteSymbolReference
class ExpressionSymbolInliner:        @Override
        public Expression rewriteSymbolReference(SymbolReference node, Void context, ExpressionTreeRewriter<Void> treeRewriter)
        {
            if (excludedNames.contains(node.getName())) {
                return node;
            }

            Expression expression = mapping.apply(Symbol.from(node));
            checkState(expression != null, "Cannot resolve symbol %s", node.getName());
            return expression;
        }