}

  public void testToString() throws IOException {
    File asciiFile = getTestFile("ascii.txt");
    File i18nFile = getTestFile("i18n.txt");
    assertEquals(ASCII, Files.toString(asciiFile, Charsets.US_ASCII));
    assertEquals(I18N, Files.toString(i18nFile, Charsets.UTF_8));
    assertThat(Files.toString(i18nFile, Charsets.US_ASCII)).isNotEqualTo(I18N);
  }

  public void testWriteString() throws IOException {

  public void testWhyUsAsciiIsDangerous() {
    byte[] b1 = "朝日新聞".getBytes(Charsets.US_ASCII);
    byte[] b2 = "聞朝日新".getBytes(Charsets.US_ASCII);
    byte[] b3 = "????".getBytes(Charsets.US_ASCII);
    byte[] b4 = "ニュース".getBytes(Charsets.US_ASCII);
    byte[] b5 = "スューー".getBytes(Charsets.US_ASCII);
    // Assert they are all equal (using the transitive property)
    assertTrue(Arrays.equals(b1, b2));

  private Charsets() {}

  /**
   * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
   *
   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
   * java.nio.charset.StandardCharsets#US_ASCII} instead.
   *
   */
  @J2ktIncompatible
  @GwtIncompatible // Charset not supported by GWT
  public static final Charset US_ASCII = Charset.forName("US-ASCII");

  /**

   *
   * <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)}.
   *

      return "CharMatcher.breakingWhitespace()";
    }
  }

  /** Implementation of {@link #ascii()}. */
  private static final class Ascii extends NamedFastMatcher {

    static final CharMatcher INSTANCE = new Ascii();

    Ascii() {
      super("CharMatcher.ascii()");
    }

    @Override
    public boolean matches(char c) {
      return c <= '\u007f';
    }
  }

          }
        };
    EscaperAsserts.assertBasic(deletingEscaper);
    assertEquals(
        "Everything outside the printable ASCII range is deleted.",
        deletingEscaper.escape(
            "\tEverything\0 outside the\uD800\uDC00 "
                + "printable ASCII \uFFFFrange is \u007Fdeleted.\n"));
  }

  public void testReplacementPriority() throws IOException {
    UnicodeEscaper replacingEscaper =

    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(I18N, Resources.toString(resource, Charsets.UTF_8));
    assertThat(Resources.toString(resource, Charsets.US_ASCII)).isNotEqualTo(I18N);
  }

  public void testToByteArray() throws IOException {
    URL resource = getClass().getResource("testdata/i18n.txt");

          .build();

  public void testHashing() {
    for (String stringToTest : INPUTS) {
      for (String algorithmToTest : ALGORITHMS.keySet()) {
        assertMessageDigestHashing(HashTestUtils.ascii(stringToTest), algorithmToTest);
      }
    }
  }

  public void testPutAfterHash() {
    Hasher sha1 = Hashing.sha1().newHasher();

    assertEquals(
        "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12",

package com.google.common.net;


import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Ascii;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.testing.EqualsTester;

      fail(msg);
    } catch (IllegalArgumentException expected) {
      assertThat(expected).hasMessageThat().isEqualTo(msg);
    }
  }

  /** Helper to manually escape a 7-bit ascii character */
  private String escapeAscii(char c) {
    Preconditions.checkArgument(c < 128);
    String hex = "0123456789ABCDEF";
    return "%" + hex.charAt((c >> 4) & 0xf) + hex.charAt(c & 0xf);
  }