presto-main/src/main/java/io/prestosql/sql/planner/optimizations/StreamPropertyDerivations.java/StreamProperties/equals
class StreamProperties:        @Override
        public boolean equals(Object obj)
        {
            if (this == obj) {
                return true;
            }
            if (obj == null || getClass() != obj.getClass()) {
                return false;
            }
            StreamProperties other = (StreamProperties) obj;
            return Objects.equals(this.distribution, other.distribution) &&
                    Objects.equals(this.partitioningColumns, other.partitioningColumns);
        }