hollow/src/main/java/com/netflix/hollow/api/consumer/index/UniqueKeyIndex.java
public static <T extends HollowObject> Builder<T> from(HollowConsumer consumer, Class<T> uniqueType) {
        Objects.requireNonNull(consumer);
        Objects.requireNonNull(uniqueType);
        return new Builder<>(consumer, uniqueType);
    }
public static <T extends HollowObject> Builder<T> from(HollowConsumer consumer, Class<T> uniqueType) {
        Objects.requireNonNull(consumer);
        Objects.requireNonNull(uniqueType);
        return new Builder<>(consumer, uniqueType);
    }
Starts the building of a {@link UniqueKeyIndex}.

@param consumer the consumer containing instances of the given unique type
@param uniqueType the unique type
@param <T> the unique type
@return a builder