text: /*
   * Licensed to Elasticsearch under one or more contributor
   * license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright
   * ownership. Elasticsearch licenses this file to you 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 org.elasticsearch.search.suggest;
  
  import org.apache.lucene.search.IndexSearcher;
  import org.apache.lucene.util.CharsRefBuilder;
  
  import java.io.IOException;
  
  public abstract class Suggester<T extends SuggestionSearchContext.SuggestionContext> {
  
      protected abstract Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>>
          innerExecute(String name, T suggestion, IndexSearcher searcher, CharsRefBuilder spare) throws IOException;
  
      public Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>>
                  execute(String name, T suggestion, IndexSearcher searcher, CharsRefBuilder spare) throws IOException {
          // #3469 We want to ignore empty shards
  
          if (searcher.getIndexReader().numDocs() == 0) {
              return null;
          }
          return innerExecute(name, suggestion, searcher, spare);
      }
  
  }
  