}

    /**
     * Joins array or list elements into a single space-separated string.
     *
     * @param input the input object (String[], List, or String)
     * @return joined string with elements separated by spaces, or empty string if invalid input
     */
    public static String join(final Object input) {
        String[] values = null;

    assertThat(ArbitraryInstances.get(Currency.class).getCurrencyCode()).isNotNull();
    assertThat(ArbitraryInstances.get(Locale.class)).isNotNull();
    assertThat(ArbitraryInstances.get(Joiner.class).join(ImmutableList.of("a"))).isNotNull();
    assertThat(ArbitraryInstances.get(Splitter.class).split("a,b")).isNotNull();
    assertThat(ArbitraryInstances.get(com.google.common.base.Optional.class)).isAbsent();

    return user_id


# Un modelo de Pydantic
class User(BaseModel):
    id: int
    name: str
    joined: date
```

Que luego puede ser usado como:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

/// info | Información

    String oldClassPath = JAVA_CLASS_PATH.value();
    System.setProperty(PATH_SEPARATOR.key(), ":");
    System.setProperty(
        JAVA_CLASS_PATH.key(),
        Joiner.on(":")
            .join(
                "relative/path/to/some.jar",
                "/absolute/path/to/some.jar",
                "relative/path/to/class/root",
                "/absolute/path/to/class/root"));
    try {

    assertThat(ArbitraryInstances.get(Currency.class).getCurrencyCode()).isNotNull();
    assertThat(ArbitraryInstances.get(Locale.class)).isNotNull();
    assertThat(ArbitraryInstances.get(Joiner.class).join(ImmutableList.of("a"))).isNotNull();
    assertThat(ArbitraryInstances.get(Splitter.class).split("a,b")).isNotNull();
    assertThat(ArbitraryInstances.get(com.google.common.base.Optional.class)).isAbsent();

  }

  /**
   * Waits for the specified time (in milliseconds) for the thread to terminate (using {@link
   * Thread#join(long)}), else interrupts the thread (in the hope that it may terminate later) and
   * fails.
   */
  void awaitTermination(Thread t, long timeoutMillis) {
    try {
      t.join(timeoutMillis);
    } catch (InterruptedException ie) {
      threadUnexpectedException(ie);
    } finally {

    String oldClassPath = JAVA_CLASS_PATH.value();
    System.setProperty(PATH_SEPARATOR.key(), ":");
    System.setProperty(
        JAVA_CLASS_PATH.key(),
        Joiner.on(":")
            .join(
                "relative/path/to/some.jar",
                "/absolute/path/to/some.jar",
                "relative/path/to/class/root",
                "/absolute/path/to/class/root"));
    try {

        }
        String prefix = (moduleName == null) ? "" : (moduleName + '=');
        StringJoiner joiner = new StringJoiner(File.pathSeparator, prefix, "");
        joiner.setEmptyValue("");
        for (Path p : paths) {
            joiner.add(p.toString());
        }
        String value = joiner.toString();
        if (value.isEmpty()) {
            return new String[0];
        }

  }

  public void testJoin() {
    assertThat(SignedBytes.join(",", EMPTY)).isEmpty();
    assertThat(SignedBytes.join(",", ARRAY1)).isEqualTo("1");
    assertThat(SignedBytes.join(",", (byte) 1, (byte) 2)).isEqualTo("1,2");
    assertThat(SignedBytes.join("", (byte) 1, (byte) 2, (byte) 3)).isEqualTo("123");
    assertThat(SignedBytes.join(",", (byte) -128, (byte) -1)).isEqualTo("-128,-1");
  }

  }

  public void testJoin() {
    assertThat(UnsignedBytes.join(",", new byte[] {})).isEmpty();
    assertThat(UnsignedBytes.join(",", new byte[] {(byte) 1})).isEqualTo("1");
    assertThat(UnsignedBytes.join(",", (byte) 1, (byte) 2)).isEqualTo("1,2");
    assertThat(UnsignedBytes.join("", (byte) 1, (byte) 2, (byte) 3)).isEqualTo("123");
    assertThat(UnsignedBytes.join(",", (byte) 128, (byte) -1)).isEqualTo("128,255");
  }