@Override
        public boolean equals(Object o) {
            if (o == this) return true;
            if ( ! (o instanceof StandardTarget other)) return false;

            if ( ! Objects.equals(other.chain.getId(), this.chain.getId())) return false;
            if ( ! Objects.equals(other.target, this.target)) return false;
            return true;
        }
A handler representing a target created by the federation logic. 
This is a value object, to ensure that identical target invocations are not invoked multiple times.
container-search/src/main/java/com/yahoo/search/federation/FederationSearcher.java