### Question:
BaseHeader implements ISOHeader, Loggeable { public byte[] pack() { return header != null ? header.clone() : null; } BaseHeader();  BaseHeader(byte[] header); Object clone(); byte[] pack(); int unpack(byte[] header); int getLength(); void setDestination(String dst); void setSource(String src); String getDestination(); String getSource(); void swapDirection(); void dump(PrintStream p, String indent); void setAsciiEncoding(boolean asciiEncoding); boolean isAsciiEncoding();  }### Answer:
@Test public void testPack() throws Throwable { byte[] header = new byte[3]; BaseHeader baseHeader = new BaseHeader(header); byte[] header2 = new byte[3]; baseHeader.unpack(header2); byte[] result = baseHeader.pack(); assertTrue(Arrays.equals(header2, result), "result"); assertEquals((byte) 0, header2[0], "header2[0]"); }