StringBuilder builder = new StringBuilder();
    Writer writer = new AppendableWriter(builder);

    writer.write("Hello".toCharArray());
    writer.write(',');
    writer.write(0xBEEF0020); // only lower 16 bits are important
    writer.write("Wo");
    writer.write("Whirled".toCharArray(), 3, 2);
    writer.write("Mad! Mad, I say", 2, 2);

    assertEquals("Hello, World!", builder.toString());
  }

  public void testCharsIgnored() {
    for (char c : IGNORED.toCharArray()) {
      String str = String.valueOf(c);
      assertEquals(str, c, Ascii.toLowerCase(c));
      assertEquals(str, c, Ascii.toUpperCase(c));
      assertFalse(str, Ascii.isLowerCase(c));
      assertFalse(str, Ascii.isUpperCase(c));
    }
  }

  public void testCharsLower() {
    for (char c : LOWER.toCharArray()) {
      String str = String.valueOf(c);

        // Example if you want to combine multiple keystore types
        // KeyStore.Builder.newInstance("PKCS12", null, File("keystore.p12"), PasswordProtection("rosebud".toCharArray()))
      )

    val keyManagerFactory = KeyManagerFactory.getInstance("NewSunX509")
    keyManagerFactory.init(KeyStoreBuilderParameters(builderList))

import java.net.Authenticator
import java.net.PasswordAuthentication

class RecordingAuthenticator(
  private val authentication: PasswordAuthentication? =
    PasswordAuthentication(
      "username",
      "password".toCharArray(),
    ),
) : Authenticator() {
  val calls = mutableListOf<String>()

  override fun getPasswordAuthentication(): PasswordAuthentication? {
    calls.add(

    CharEscaper wrappingEscaper =
        new ArrayBasedCharEscaper(NO_REPLACEMENTS, 'A', 'Z') {
          @Override
          protected char[] escapeUnsafe(char c) {
            return ("{" + c + "}").toCharArray();
          }
        };
    EscaperAsserts.assertBasic(wrappingEscaper);
    // '[' and '@' lie either side of [A-Z].
    assertThat(wrappingEscaper.escape("[FOO@BAR]")).isEqualTo("{[}FOO{@}BAR{]}");
  }

    try (InputStream in = new FileInputStream(keystoreFile)) {
      keystore.load(in, password.toCharArray());
    }
    KeyManagerFactory keyManagerFactory =
        KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
    keyManagerFactory.init(keystore, password.toCharArray());

    TrustManagerFactory trustManagerFactory =

  private static final char[] plusSign = {'+'};

  // Percent escapers output upper case hex digits (uri escapers require this).
  private static final char[] upperHexDigits = "0123456789ABCDEF".toCharArray();

  /** If true we should convert space to the {@code +} character. */
  private final boolean plusForSpace;

  /**
   * An array of flags where for any {@code char c} if {@code safeOctets[c]} is true then {@code c}

            + "\u0ce6\u0d66\u0e50\u0ed0\u0f20\u1040\u1090\u17e0\u1810\u1946"
            + "\u19d0\u1b50\u1bb0\u1c40\u1c50\ua620\ua8d0\ua900\uaa50\uff10";
    for (char base : zeros.toCharArray()) {
      for (int offset = 0; offset < 10; offset++) {
        sb.append((char) (base + offset));
      }
    }
    ALL_DIGITS = sb.toString();
  }

  /** Sample CharMatcher instances for benchmarking. */

            + "\u0ce6\u0d66\u0e50\u0ed0\u0f20\u1040\u1090\u17e0\u1810\u1946"
            + "\u19d0\u1b50\u1bb0\u1c40\u1c50\ua620\ua8d0\ua900\uaa50\uff10";
    for (char base : zeros.toCharArray()) {
      for (int offset = 0; offset < 10; offset++) {
        sb.append((char) (base + offset));
      }
    }
    ALL_DIGITS = sb.toString();
  }

  /** Sample CharMatcher instances for benchmarking. */

    UnicodeEscaper wrappingEscaper =
        new ArrayBasedUnicodeEscaper(NO_REPLACEMENTS, 'A', 'Z', null) {
          @Override
          protected char[] escapeUnsafe(int c) {
            return ("{" + (char) c + "}").toCharArray();
          }
        };
    EscaperAsserts.assertBasic(wrappingEscaper);
    // '[' and '@' lie either side of [A-Z].
    assertThat(wrappingEscaper.escape("[FOO@BAR]")).isEqualTo("{[}FOO{@}BAR{]}");
  }