package com.google.copybara;

import java.time.Instant;
import javax.annotation.Nullable;

/**
 * A reference of {@link Origin}.
 *
 * <p>For example, in Git it would be a reference to a commit SHA-1.
 */
public interface Reference {

  /**
   * Reads the timestamp of this reference from the repository, or {@code null} if this repo type
   * does not support it. This is the {@link Instant} from the UNIX epoch when the reference was
   * submitted to the source repository.
   */
  @Nullable
  Instant readTimestamp() throws RepoException;

  /**
   * String representation of the reference that can be parsed by {@link Origin#resolve(String)}.
   *
   * <p> Unlike {@link #toString()} method, this method is guaranteed to be stable.
   */
  String asString();

  /**
   * Label name to be used in when creating a commit message in the destination to refer to a
   * reference. For example "Git-RevId".
   */
  String getLabelName();
}

@@ -1,8 +1,604 @@
+/*%0A * Copyright (C) 2016 Google Inc.%0A *%0A * Licensed under the Apache License, Version 2.0 (the %22License%22);%0A * you may not use this file except in compliance with the License.%0A * You may obtain a copy of the License at%0A *%0A * http://www.apache.org/licenses/LICENSE-2.0%0A *%0A * Unless required by applicable law or agreed to in writing, software%0A * distributed under the License is distributed on an %22AS IS%22 BASIS,%0A * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.%0A * See the License for the specific language governing permissions and%0A * limitations under the License.%0A */%0A%0A
 package 

Add missing license header