/*
 * 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.ingest.core;

import java.util.Map;

/**
 * Abstraction for the ingest template engine: allows to compile a template into a {@link Template} object.
 * A compiled template can be executed by calling its {@link Template#execute(Map)} method.
 */
public interface TemplateService {

    Template compile(String template);

    interface Template {

        String execute(Map<String, Object> model);

        String getKey();
    }
}

@@ -898,11 +898,106 @@
 gine
-: a
+ used to decouple %7B@link IngestDocument%7D from %7B@link org.elasticsearch.script.ScriptService%7D.%0A * A
 llow
@@ -1026,16 +1026,24 @@
 e into a
+n ingest
  %7B@link 

clarify comment in TemplateService, explain why we have this class