presto-main/src/main/java/io/prestosql/sql/planner/plan/WindowNode.java/Specification/equals
class Specification:        @Override
        public boolean equals(Object obj)
        {
            if (this == obj) {
                return true;
            }

            if (obj == null || getClass() != obj.getClass()) {
                return false;
            }

            Specification other = (Specification) obj;

            return Objects.equals(this.partitionBy, other.partitionBy) &&
                    Objects.equals(this.orderingScheme, other.orderingScheme);
        }