presto-main/src/main/java/io/prestosql/sql/planner/OrderingScheme.java/OrderingScheme/OrderingScheme
class OrderingScheme:    @JsonCreator
    public OrderingScheme(@JsonProperty("orderBy") List<Symbol> orderBy, @JsonProperty("orderings") Map<Symbol, SortOrder> orderings)
    {
        requireNonNull(orderBy, "orderBy is null");
        requireNonNull(orderings, "orderings is null");
        checkArgument(!orderBy.isEmpty(), "orderBy is empty");
        checkArgument(orderings.keySet().equals(ImmutableSet.copyOf(orderBy)), "orderBy keys and orderings don't match");
        this.orderBy = ImmutableList.copyOf(orderBy);
        this.orderings = ImmutableMap.copyOf(orderings);
    }