}

  public void testSkipNulls() {
    Joiner skipNulls = J.skipNulls();
    checkNoOutput(skipNulls, iterable);
    checkNoOutput(skipNulls, iterableNull);
    checkNoOutput(skipNulls, iterableNullNull);
    checkNoOutput(skipNulls, iterableFourNulls);
    checkResult(skipNulls, iterable1, "1");
    checkResult(skipNulls, iterable12, "1-2");
    checkResult(skipNulls, iterable123, "1-2-3");

 *
 * {@snippet :
 * Joiner joiner = Joiner.on("; ").skipNulls();
 *  . . .
 * return joiner.join("Harry", null, "Ron", "Hermione");
 * }
 *
 * <p>This returns the string {@code "Harry; Ron; Hermione"}. Note that all input elements are
 * converted to strings using {@link Object#toString()} before being appended.
 *
 * <p>If neither {@link #skipNulls()} nor {@link #useForNull(String)} is specified, the joining

 *
 * {@snippet :
 * Joiner joiner = Joiner.on("; ").skipNulls();
 *  . . .
 * return joiner.join("Harry", null, "Ron", "Hermione");
 * }
 *
 * <p>This returns the string {@code "Harry; Ron; Hermione"}. Note that all input elements are
 * converted to strings using {@link Object#toString()} before being appended.
 *
 * <p>If neither {@link #skipNulls()} nor {@link #useForNull(String)} is specified, the joining

   *       versa.
   *   <li>Inequality check is not performed against state mutation methods such as {@link
   *       List#add}, or functional update methods such as {@link
   *       com.google.common.base.Joiner#skipNulls}.
   *   <li>If the constructor or factory method used to construct instance takes a parameter that
   *       {@link AbstractPackageSanityTests} doesn't know how to construct, the test will fail.

   *   <li>Inequality check is not performed against state mutation methods such as {@link
   *       List#add}, or functional update methods such as {@link
   *       com.google.common.base.Joiner#skipNulls}.
   * </ul>
   *
   * <p>Note that constructors taking a builder object cannot be tested effectively because
   * semantics of builder can be arbitrarily complex. Still, a factory class can be created in the

   *   <li>Inequality check is not performed against state mutation methods such as {@link
   *       List#add}, or functional update methods such as {@link
   *       com.google.common.base.Joiner#skipNulls}.
   * </ul>
   *
   * <p>Note that constructors taking a builder object cannot be tested effectively because
   * semantics of builder can be arbitrarily complex. Still, a factory class can be created in the

    String expected = begin + end;
    assertEquals(expected.charAt(0), joinedReader.read());
    CharStreams.skipFully(joinedReader, 1);
    assertEquals(expected.charAt(2), joinedReader.read());
    CharStreams.skipFully(joinedReader, 4);
    assertEquals(expected.charAt(7), joinedReader.read());
    CharStreams.skipFully(joinedReader, 1);
    assertEquals(expected.charAt(9), joinedReader.read());
    assertEquals(-1, joinedReader.read());

    assertThrows(EOFException.class, () -> CharStreams.skipFully(reader, 6));
  }

  public void testSkipFully() throws IOException {
    String testString = "abcdef";
    Reader reader = new StringReader(testString);

    assertEquals(testString.charAt(0), reader.read());
    CharStreams.skipFully(reader, 1);
    assertEquals(testString.charAt(2), reader.read());
    CharStreams.skipFully(reader, 2);

    assertThrows(EOFException.class, () -> CharStreams.skipFully(reader, 6));
  }

  public void testSkipFully() throws IOException {
    String testString = "abcdef";
    Reader reader = new StringReader(testString);

    assertEquals(testString.charAt(0), reader.read());
    CharStreams.skipFully(reader, 1);
    assertEquals(testString.charAt(2), reader.read());
    CharStreams.skipFully(reader, 2);

  @Override
  void readFully(byte[] b);

  @Override
  void readFully(byte[] b, int off, int len);

  // not guaranteed to skip n bytes so result should NOT be ignored
  // use ByteStreams.skipFully or one of the read methods instead
  @Override
  int skipBytes(int n);

  @CanIgnoreReturnValue // to skip a byte
  @Override
  boolean readBoolean();

  @CanIgnoreReturnValue // to skip a byte
  @Override