Mockito spy example

MockitoSpyExample.java

import static org.mockito.Mockito.*;
import java.util.HashMap;
import java.util.Map;
import org.junit.Test;

public class MockitoSpyExample {
  @Test
  public void spyExample_nominal_case_Test() {
    Map<String, String> hashMap = new HashMap<String, String>();
    Map<String, String> mapSpy = spy(hashMap);
    System.out.println(mapSpy.get("key")); 
    mapSpy.put("key", "Test value");
    System.out.println(mapSpy.get("key")); // Will print "Test value".
    when(mapSpy.get("key")).thenReturn("Mocked value");
    System.out.println(mapSpy.get("key")); // Will print "Mocked vqlue".
  }
}