presto-main/src/main/java/io/prestosql/sql/planner/OrderingScheme.java/OrderingScheme/equals
class OrderingScheme:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        OrderingScheme that = (OrderingScheme) o;
        return Objects.equals(orderBy, that.orderBy) &&
                Objects.equals(orderings, that.orderings);
    }