func (b *Buffer) String() string {
	if b == nil {
		// Special case, useful in debugging.
		return "<nil>"
	}
	return string(b.buf[b.off:])
}

// empty reports whether the unread portion of the buffer is empty.
func (b *Buffer) empty() bool { return len(b.buf) <= b.off }

// Len returns the number of bytes of the unread portion of the buffer;
// b.Len() == len(b.Bytes()).

  public void testConcat() {
    assertThat(Floats.concat()).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Floats.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Floats.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);

  }

  public void testConcat() {
    assertThat(Ints.concat()).isEqualTo(EMPTY);
    assertThat(Ints.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Ints.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Ints.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Ints.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Ints.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Ints.concat(ARRAY1, ARRAY1, ARRAY1))

  public void testConcat() {
    assertThat(Floats.concat()).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Floats.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Floats.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Floats.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);

        assertArrayEquals(key, transport.getServerEncryptionKey());
        verify(transport).getServerEncryptionKey();

        // Empty array
        byte[] empty = new byte[0];
        when(transport.getServerEncryptionKey()).thenReturn(empty);
        assertArrayEquals(empty, transport.getServerEncryptionKey());

        // Null
        when(transport.getServerEncryptionKey()).thenReturn(null);

    @Nonnull
    Stream<P> problems(BuilderProblem.Severity severity);

    /**
     * Creates an "empty" problem collector that doesn't store any problems.
     *
     * @param <P> the type of problem
     * @return an empty problem collector
     */
    @Nonnull
    static <P extends BuilderProblem> ProblemCollector<P> empty() {
        return new ProblemCollector<>() {
            @Override

     * format using the specified encoding scheme.
     *
     * @param s
     *            The string to be converted. Must not be {@literal null} or empty.
     * @param enc
     *            The encoding scheme. Must not be {@literal null} or empty.
     * @return The string encoded in <code>application/x-www-form-urlencoded</code> format.
     */
    public static String encode(final String s, final String enc) {

    }

    @Test
    @DisplayName("EmptyIterator should follow Iterator contract for empty collections")
    void testIteratorContract() {
        // Given - typical Iterator usage pattern

        // When & Then - verify empty collection behavior
        assertFalse(emptyIterator.hasNext(), "Empty iterator should have no next element");

     *
     * @param baseDirectory the base directory for relativizing paths during matching
     * @param includes the patterns of files to include, or null/empty for including all files
     * @param excludes the patterns of files to exclude, or null/empty for no exclusion
     * @param useDefaultExcludes whether to augment excludes with default SCM exclusion patterns

      assertThat(expected.message).isEqualTo("Code 1005 is reserved and may not be used.")
    }
  }

  @Test fun serverEmptyPing() {
    serverWriter.writePing(EMPTY)
    assertData("8900")
  }

  @Test fun clientEmptyPing() {
    clientWriter.writePing(EMPTY)
    assertData("898060b420bb")
  }

  @Test fun serverPingWithPayload() {
    serverWriter.writePing("Hello".encodeUtf8())
    assertData("890548656c6c6f")