presto-main/src/main/java/io/prestosql/sql/planner/ExpressionInterpreter.java/ExpressionInterpreter/visitArithmeticBinary
class ExpressionInterpreter:        @Override
        protected Object visitArithmeticBinary(ArithmeticBinaryExpression node, Object context)
        {
            Object left = process(node.getLeft(), context);
            if (left == null) {
                return null;
            }
            Object right = process(node.getRight(), context);
            if (right == null) {
                return null;
            }

            if (hasUnresolvedValue(left, right)) {
                return new ArithmeticBinaryExpression(node.getOperator(), toExpression(left, type(node.getLeft())), toExpression(right, type(node.getRight())));
            }

            return invokeOperator(OperatorType.valueOf(node.getOperator().name()), types(node.getLeft(), node.getRight()), ImmutableList.of(left, right));
        }