### Question:
SfcNshHeader { public PortNumber getNshTunUdpPort() { return nshTunUdpPort; } private  SfcNshHeader(SfcNshHeaderBuilder builder); boolean isValid(SfcNshHeader sfcNshHeader); Ipv4Address getNshTunIpDst(); PortNumber getNshTunUdpPort(); Long getNshNspToChain(); Short getNshNsiToChain(); Long getNshNspFromChain(); Short getNshNsiFromChain(); Long getNshMetaC1(); Long getNshMetaC2(); static Long convertIpAddressToLong(Ipv4Address ipv4Address); static int getType();  }### Answer:
@Test public void tunUdpPortTest() { Assert.assertEquals(nshTunUdpPort, header.getNshTunUdpPort()); builder.setNshTunUdpPort(null); header = builder.build(); Assert.assertNull(header.getNshTunUdpPort()); }