assertEquals(LOWER, Ascii.toLowerCase(UPPER));
    assertSame(LOWER, Ascii.toLowerCase(LOWER));
    assertEquals(IGNORED, Ascii.toLowerCase(IGNORED));
    assertEquals("foobar", Ascii.toLowerCase("fOobaR"));
  }

  public void testToUpperCase() {
    assertEquals(UPPER, Ascii.toUpperCase(LOWER));
    assertSame(UPPER, Ascii.toUpperCase(UPPER));
    assertEquals(IGNORED, Ascii.toUpperCase(IGNORED));

    StringBuilder builder = new StringBuilder();
    long copied =
        CharStreams.copy(
            wrapAsGenericReadable(new StringReader(ASCII)), wrapAsGenericAppendable(builder));
    assertEquals(ASCII, builder.toString());
    assertEquals(ASCII.length(), copied);

    StringBuilder builder2 = new StringBuilder();
    copied =
        CharStreams.copy(

    StringBuilder builder = new StringBuilder();
    long copied =
        CharStreams.copy(
            wrapAsGenericReadable(new StringReader(ASCII)), wrapAsGenericAppendable(builder));
    assertEquals(ASCII, builder.toString());
    assertEquals(ASCII.length(), copied);

    StringBuilder builder2 = new StringBuilder();
    copied =
        CharStreams.copy(

   *
   * <p>This method accepts non-ASCII digits, for example {@code "１９２.１６８.０.１"} (those are fullwidth
   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *

// given ASCII character in the set. The 128-bits of the lower 16 bytes,
// starting with the least-significant bit of the lowest word to the
// most-significant bit of the highest word, map to the full range of all
// 128 ASCII characters. The 128-bits of the upper 16 bytes will be zeroed,
// ensuring that any non-ASCII character will be reported as not in the set.

      BaseEncoding encoding, String decoded, String encoded) {
    testEncodingWithSeparators(encoding, decoded, encoded);
    testEncodingWithSeparators(encoding.upperCase(), decoded, Ascii.toUpperCase(encoded));
    testEncodingWithSeparators(encoding.lowerCase(), decoded, Ascii.toLowerCase(encoded));
  }

  private static void testEncodingWithSeparators(
      BaseEncoding encoding, String decoded, String encoded) {

    checkArgument(!token.isEmpty());
    return Ascii.toLowerCase(token);
  }

  private static String normalizeParameterValue(String attribute, String value) {
    checkNotNull(value); // for GWT
    checkArgument(ascii().matchesAllOf(value), "parameter values must be ASCII: %s", value);
    return CHARSET_ATTRIBUTE.equals(attribute) ? Ascii.toLowerCase(value) : value;
  }

  /**

   * (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Integer#parseInt(String)}, this method returns {@code null} instead of
   * throwing an exception if parsing fails. Additionally, this method only accepts ASCII digits,
   * and returns {@code null} if non-ASCII digits are present in the string.
   *

    boolean canDecode(char ch) {
      return ch <= Ascii.MAX && decodabet[ch] != -1;
    }

    int decode(char ch) throws DecodingException {
      if (ch > Ascii.MAX) {
        throw new DecodingException("Unrecognized character: 0x" + Integer.toHexString(ch));
      }
      int result = decodabet[ch];
      if (result == -1) {
        if (ch <= 0x20 || ch == Ascii.MAX) {

import static com.google.common.collect.Lists.charactersOf;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Ascii;
import com.google.common.collect.testing.SpliteratorTester;
import java.util.Arrays;
import java.util.List;
import java.util.Spliterator;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;