presto-main/src/main/java/io/prestosql/sql/planner/plan/OffsetNode.java/OffsetNode/OffsetNode
class OffsetNode:    @JsonCreator
    public OffsetNode(
            @JsonProperty("id") PlanNodeId id,
            @JsonProperty("source") PlanNode source,
            @JsonProperty("count") long count)
    {
        super(id);

        requireNonNull(source, "source is null");
        checkArgument(count >= 0, "count must be greater than or equal to zero");

        this.source = source;
        this.count = count;
    }