presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionAnalyzer.java/ExpressionAnalyzer/visitTryExpression
class ExpressionAnalyzer:        @Override
        public Type visitTryExpression(TryExpression node, StackableAstVisitorContext<Context> context)
        {
            Type type = process(node.getInnerExpression(), context);
            return setExpressionType(node, type);
        }