presto-main/src/main/java/io/prestosql/sql/gen/JoinCompiler.java/CacheKey/equals
class CacheKey:        @Override
        public boolean equals(Object obj)
        {
            if (this == obj) {
                return true;
            }
            if (!(obj instanceof CacheKey)) {
                return false;
            }
            CacheKey other = (CacheKey) obj;
            return Objects.equals(this.types, other.types) &&
                    Objects.equals(this.outputChannels, other.outputChannels) &&
                    Objects.equals(this.joinChannels, other.joinChannels) &&
                    Objects.equals(this.sortChannel, other.sortChannel);
        }