content: package com.alibaba.cloudapp.model;
  
  import org.junit.Before;
  import org.junit.Test;
  
  import java.util.Collections;
  import java.util.List;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotEquals;
  
  public class PairsTest {
      
      private Pairs<String, String> pairsUnderTest;
      
      @Before
      public void setUp() throws Exception {
          pairsUnderTest = new Pairs<>();
      }
      
      @Test
      public void testOf() {
          // Setup
          // Run the test
          final Pairs<String, String> result = pairsUnderTest.of("key", "value");
          
          // Verify the results
      }
      
      @Test
      public void testToList() {
          final List<Pairs.Pair<String, ? extends String>> result = pairsUnderTest.toList();
      }
      
      @Test
      public void testToPairs() {
          // Run the test
          final Pairs<String, String> result = Pairs.toPairs("key", "value");
          assertEquals(Pairs.toPairs("key", "value"), result);
          assertEquals(Collections.singletonList(new Pairs.Pair<>("key", "value")),
                       result.toList()
          );
          
          assertNotEquals(Pairs.toPairs("key", "value1"), result);
          assertNotEquals(new Object(), result);
          
          assertNotEquals(Pairs.toPairs(new Object(), new Object()), result);
          
      }
      
  }
  