content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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.
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  package org.apache.beam.sdk.transforms;
  
  import java.util.Arrays;
  import org.apache.beam.sdk.coders.BigEndianIntegerCoder;
  import org.apache.beam.sdk.coders.KvCoder;
  import org.apache.beam.sdk.coders.NullableCoder;
  import org.apache.beam.sdk.coders.StringUtf8Coder;
  import org.apache.beam.sdk.testing.NeedsRunner;
  import org.apache.beam.sdk.testing.PAssert;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.testing.ValidatesRunner;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for KvSwap transform. */
  @RunWith(JUnit4.class)
  @SuppressWarnings({
    "rawtypes", // TODO(https://github.com/apache/beam/issues/20447)
    "unchecked",
  })
  public class KvSwapTest {
    private static final KV<String, Integer>[] TABLE =
        new KV[] {
          KV.of("one", 1),
          KV.of("two", 2),
          KV.of("three", 3),
          KV.of("four", 4),
          KV.of("dup", 4),
          KV.of("dup", 5),
          KV.of("null", null),
        };
  
    private static final KV<String, Integer>[] EMPTY_TABLE = new KV[] {};
  
    @Rule public final TestPipeline p = TestPipeline.create();
  
    @Test
    @Category(ValidatesRunner.class)
    public void testKvSwap() {
      PCollection<KV<String, Integer>> input =
          p.apply(
              Create.of(Arrays.asList(TABLE))
                  .withCoder(
                      KvCoder.of(
                          StringUtf8Coder.of(), NullableCoder.of(BigEndianIntegerCoder.of()))));
  
      PCollection<KV<Integer, String>> output = input.apply(KvSwap.create());
  
      PAssert.that(output)
          .containsInAnyOrder(
              KV.of(1, "one"),
              KV.of(2, "two"),
              KV.of(3, "three"),
              KV.of(4, "four"),
              KV.of(4, "dup"),
              KV.of(5, "dup"),
              KV.of((Integer) null, "null"));
      p.run();
    }
  
    @Test
    @Category(NeedsRunner.class)
    public void testKvSwapEmpty() {
      PCollection<KV<String, Integer>> input =
          p.apply(
              Create.of(Arrays.asList(EMPTY_TABLE))
                  .withCoder(KvCoder.of(StringUtf8Coder.of(), BigEndianIntegerCoder.of())));
  
      PCollection<KV<Integer, String>> output = input.apply(KvSwap.create());
  
      PAssert.that(output).empty();
      p.run();
    }
  }
  