presto-main/src/main/java/io/prestosql/sql/planner/optimizations/PredicatePushDown.java/Rewriter/symbolForExpression
class Rewriter:        private Symbol symbolForExpression(Expression expression)
        {
            if (expression instanceof SymbolReference) {
                return Symbol.from(expression);
            }

            return symbolAllocator.newSymbol(expression, typeAnalyzer.getType(session, symbolAllocator.getTypes(), expression));
        }