Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertThat(bimap.get("canada")).isEqualTo("dollar");
    assertThat(bimap.inverse().get("dollar")).isEqualTo("canada");
  }

  private static final int N = 1000;

    Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertThat(bimap.get("canada")).isEqualTo("dollar");
    assertThat(bimap.inverse().get("dollar")).isEqualTo("canada");
  }

  private static final int N = 1000;

@GwtCompatible
@NullUnmarked
public class EnumHashBiMapTest extends TestCase {
  private enum Currency {
    DOLLAR,
    FRANC,
    PESO,
    POUND,
    YEN
  }

  private enum Country {
    CANADA,
    CHILE,
    JAPAN,
    SWITZERLAND,
    UK
  }

  @AndroidIncompatible // test-suite builders
  public static final class EnumHashBiMapGenerator implements TestBiMapGenerator<Country, String> {

@GwtCompatible
@NullUnmarked
public class EnumHashBiMapTest extends TestCase {
  private enum Currency {
    DOLLAR,
    FRANC,
    PESO,
    POUND,
    YEN
  }

  private enum Country {
    CANADA,
    CHILE,
    JAPAN,
    SWITZERLAND,
    UK
  }

  @AndroidIncompatible // test-suite builders
  public static final class EnumHashBiMapGenerator implements TestBiMapGenerator<Country, String> {

ium","belize","benin","bermuda","bhutan","bolivia","bonaire","bosnia and herzegovina","botswana","bouvet island","brazil","british indian ocean territory","brunei darussalam","bulgaria","burkina faso","burundi","cabo verde","cambodia","cameroon","canada","cayman islands","central african republic","chad","chile","china","christmas island","cocos islands","colombia","comoros","democratic republic of the congo","congo","cook islands","costa rica","côte d'ivoire","croatia","cuba","curaçao","cyprus"...

    }

    @Test
    public void test_determineAlias_multipleLocales() {
        // Test with various locale configurations
        Locale[] testLocales = { Locale.US, Locale.UK, Locale.CANADA, Locale.FRANCE, Locale.CHINA, Locale.KOREA, new Locale("es", "ES"),
                new Locale("pt", "BR") };

        for (Locale locale : testLocales) {

    unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 4);
    unfiltered.put("dog", 3);
    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);

    assertEquals(ImmutableMap.of("banana", 6), filtered.headMap("dog"));
    assertEquals(ImmutableMap.of(), filtered.headMap("banana"));
    assertEquals(ImmutableMap.of("banana", 6, "dog", 3), filtered.headMap("emu"));

			for i := 0; i < stmt.ReflectValue.Len(); i++ {
				if stmt.ReflectValue.CanAddr() {
					field.Set(stmt.Context, stmt.ReflectValue.Index(i), value)
				}
			}
		}
	case reflect.Struct:
		assignValue = func(field *schema.Field, value interface{}) {
			if stmt.ReflectValue.CanAddr() {
				field.Set(stmt.Context, stmt.ReflectValue, value)
			}
		}
	default:

				if value := reflect.Indirect(db.Statement.ReflectValue.Index(i)); value.CanAddr() {
					fc(value.Addr().Interface(), tx)
				} else {
					db.AddError(gorm.ErrInvalidValue)
					return
				}
				db.Statement.CurDestIndex++
			}
		case reflect.Struct:
			if db.Statement.ReflectValue.CanAddr() {
				fc(db.Statement.ReflectValue.Addr().Interface(), tx)
			} else {

Pero primero, vamos a revisar algunos pequeños conceptos.

## ¿Con prisa? { #in-a-hurry }

Si no te importan ninguno de estos términos y solo necesitas agregar seguridad con autenticación basada en nombre de usuario y contraseña *ahora mismo*, salta a los siguientes capítulos.

## OAuth2 { #oauth2 }

OAuth2 es una especificación que define varias maneras de manejar la autenticación y autorización.