code: /*
   * Copyright 2015 recommenders.net.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package net.recommenders.rival.evaluation.strategy;
  
  import java.util.Set;
  
  /**
   * An interface for the per-item evaluation strategy.
   *
   * @author <a href="http://github.com/abellogin">Alejandro</a>
   *
   * @param <U> generic type for users
   * @param <I> generic type for items
   */
  public interface EvaluationStrategyPerItem<U, I> {
  
      /**
       * Get the items to rank.
       *
       * @param user The user.
       * @param item The item.
       * @return The items to rank.
       */
      Set<I> getCandidateItemsToRank(U user, I item);
  }
  