presto-main/src/main/java/io/prestosql/sql/planner/planprinter/IoPlanPrinter.java/IoPlanPrinter/FormattedMarker
class IoPlanPrinter:        @JsonCreator
        public FormattedMarker(
                @JsonProperty("value") Optional<String> value,
                @JsonProperty("bound") Bound bound)
        {
            this.value = requireNonNull(value, "value is null");
            this.bound = requireNonNull(bound, "bound is null");
        }