assertThat(Buffer().isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeUtf8("abc").isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeUtf8("new\r\nlines").isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeUtf8("white\t space").isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeByte(0x80).isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeByte(0x00).isProbablyUtf8()).isFalse()

      serverSocketChannel.configureBlocking(true);
      serverSocketChannel.socket().bind(address);
    }

    @Override public int getLocalPort() {
      return 1; // A white lie. There is no local port.
    }

    @Override public SocketAddress getLocalSocketAddress() {
      return endpoint;
    }

    @Override public Socket accept() throws IOException {
      try {

274E          ; valid                  ;      ; NV8    # 6.0  NEGATIVE SQUARED CROSS MARK
274F..2752    ; valid                  ;      ; NV8    # 1.1  LOWER RIGHT DROP-SHADOWED WHITE SQUARE..UPPER RIGHT SHADOWED WHITE SQUARE
2753..2755    ; valid                  ;      ; NV8    # 6.0  BLACK QUESTION MARK ORNAMENT..WHITE EXCLAMATION MARK ORNAMENT