presto-main/src/main/java/io/prestosql/sql/planner/planprinter/IoPlanPrinter.java/IoPlan/toString
class IoPlan:        @Override
        public String toString()
        {
            return toStringHelper(this)
                    .add("inputTableColumnInfos", inputTableColumnInfos)
                    .add("outputTable", outputTable)
                    .add("estimate", estimate)
                    .toString();
        }