public String getUserId() {
        return username;
    }

    /**
     * Returns a string representation of this credential.
     *
     * @return A string representation containing the username in braces
     */
    @Override
    public String toString() {
        return "{" + username + "}";
    }

   *     argument. These are matched by position - the first {@code %s} gets {@code
   *     errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message in
   *     square braces. Unmatched placeholders will be left as-is.
   * @param errorMessageArgs the arguments to be substituted into the message template. Arguments
   *     are converted to strings using {@link String#valueOf(Object)}.

            final int openBraces = content.length() - content.replace("{", "").length();
            final int closeBraces = content.length() - content.replace("}", "").length();
            assertEquals("Braces should be balanced", openBraces, closeBraces);
        }
    }

    /**
     * Test that InputStream is properly closed even when exception occurs.
     * Verifies try-with-resources cleanup behavior.
     */

 */
internal fun String.toCanonicalHost(): String? {
  val host: String = this

  // If the input contains a :, it’s an IPv6 address.
  if (":" in host) {
    // If the input is encased in square braces "[...]", drop 'em.
    val inetAddressByteArray =
      (
        if (host.startsWith("[") && host.endsWith("]")) {
          decodeIpv6(host, 1, host.length - 1)
        } else {

        '^'.code,
        '`'.code,
        '{'.code,
        '|'.code,
        '}'.code,
      ).test(UrlComponentEncodingTester.Component.HOST)
  }

  @Test
  fun hostIpv6() {
    // Square braces are absent from host()...
    assertThat(parse("http://[::1]/").host).isEqualTo("::1")

    // ... but they're included in toString().
    assertThat(parse("http://[::1]/").toString()).isEqualTo("http://[::1]/")

   *
   *  * A regular host name, like `android.com`.
   *
   *  * An IPv4 address, like `127.0.0.1`.
   *
   *  * An IPv6 address, like `::1`. Note that there are no square braces.
   *
   *  * An encoded IDN, like `xn--n3h.net`.
   *
   * | URL                   | `host()`        |
   * | :-------------------- | :-------------- |
   * | `http://android.com/` | `"android.com"` |

    /**
     * Resolves the given host name to an array of IP addresses.
     * The host name is first converted to ASCII using IDN before resolution.
     * IPv6 addresses in bracket notation (e.g., [::1] or [2001:db8::1]) are
     * handled specially by removing the brackets before resolution.
     *
     * @param host the host name to resolve
     * @return an array of IP addresses for the host

        // Test characters just outside ranges that are not valid
        assertFalse(CharUtil.isUrlChar('`')); // backtick (just before 'a')
        assertFalse(CharUtil.isUrlChar('{')); // left brace (just after 'z')
        assertFalse(CharUtil.isUrlChar('^')); // caret (before 'a' range)
        assertFalse(CharUtil.isUrlChar('|')); // pipe (not in valid set)
    }

        String actualString = response.toString();
        assertTrue(actualString.startsWith("Trans2SetFileInformationResponse["),
                "The string representation should start with the class name.");
        assertTrue(actualString.endsWith("]"), "The string representation should end with a bracket.");
    }

 *  * [onHeaders] (unless canceled)
 *  * [onData] (optional sequence of data frames)
 *
 * As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple
 * connections should expect repetition of stream IDs.
 *
 * Return true to request cancellation of a pushed stream.  Note that this does not guarantee
 * future frames won't arrive on the stream ID.
 */
interface PushObserver {
  /**