bimap.put(Currency.DOLLAR, Country.CANADA);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, Country> map =
        ImmutableMap.of(
            Currency.DOLLAR, Country.CANADA,
            Currency.PESO, Country.CHILE,

    bimap.put(Currency.DOLLAR, Country.CANADA);
    assertEquals(Country.CANADA, bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get(Country.CANADA));
  }

  public void testCreateFromMap() {
    /* Test with non-empty Map. */
    Map<Currency, Country> map =
        ImmutableMap.of(
            Currency.DOLLAR, Country.CANADA,
            Currency.PESO, Country.CHILE,

    /* Test with non-empty Map. */
    Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertEquals("dollar", bimap.get("canada"));
    assertEquals("canada", bimap.inverse().get("dollar"));
  }

  private static final int N = 1000;

    /* Test with non-empty Map. */
    Map<String, String> map =
        ImmutableMap.of(
            "canada", "dollar",
            "chile", "peso",
            "switzerland", "franc");
    HashBiMap<String, String> bimap = HashBiMap.create(map);
    assertEquals("dollar", bimap.get("canada"));
    assertEquals("canada", bimap.inverse().get("dollar"));
  }

  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> {

        assertFalse(result.isPresent());
    }

    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) {

Pero primero, vamos a revisar algunos pequeños conceptos.

## ¿Con prisa?

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

    peer.acceptFrame() // SYN_REPLY
    peer.sendFrame().pushPromise(3, 2, headerEntries("b", "banana"))
    peer.acceptFrame() // RST_STREAM
    peer.play()

    // Play it back.
    val connection = connect(peer)
    connection.newStream(headerEntries("b", "banana"), false)

    // Verify the peer received what was expected.
    assertThat(peer.takeFrame().type).isEqualTo(Http2.TYPE_HEADERS)

   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(toImmutableListMultimap(str -> str.charAt(0), str -> str.substring(1)));
   *
   * // is equivalent to
   *
   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
   *     new ImmutableListMultimap.Builder<Character, String>()
   *         .put('b', "anana")
   *         .putAll('a', "pple", "sparagus")

    }

    @Test
    @DisplayName("Should join with multi-character delimiter")
    void testJoinWithMultiCharDelimiter() {
        String result = StringUtil.join(" - ", "apple", "banana", "cherry");
        assertEquals("apple - banana - cherry", result);
    }

    @Test
    @DisplayName("Should handle null delimiter by inserting 'null' string")
    void testJoinWithNullDelimiter() {