/**
   * FIXME rename this test in line with renamed {@link GsmAlphabet#pduToText(String)} rename.
   *
   * @param pdu
   */
  private void testPduToText(String pdu) {
    byte[] nonRefBytes = GsmAlphabet.pduToText(pdu);
    StringBuilder nonRefPdu = new StringBuilder(nonRefBytes.length);
    for (byte b : nonRefBytes) nonRefPdu.append((char) b);
    String referencePdu = ReferenceGsmAlphabet.pduToText(pdu);

    String nonRefPduString = nonRefPdu.toString();
    for (int i = 0; i < referencePdu.length(); i++) {
      assertEquals(
          "Character "
              + i
              + "was different - expected '"
              + referencePdu
              + "' but was '"
              + nonRefPduString
              + "'",
          referencePdu.charAt(i),
          nonRefPdu.charAt(i));
    }
    // Cunningly ignore the first character - the new implementation is correct, but the old one
    // was very nearly correct!
    // TODO update this testPduToText method, and the reference implementation, to the correct
    // implementation.
  }