new_contents: #!/usr/bin/python
  
  import socket
  import socks
  
  
  SERVER_IP = '127.0.0.1'
  SERVER_PORT = 1081
  
  
  if __name__ == '__main__':
      # Test 1: same source port IPv4
      sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                  socket.SOL_UDP)
      sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
      sock_out.bind(('127.0.0.1', 9000))
  
      sock_in1 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
                               socket.SOL_UDP)
      sock_in2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
                               socket.SOL_UDP)
  
      sock_in1.bind(('127.0.0.1', 9001))
      sock_in2.bind(('127.0.0.1', 9002))
  
      sock_out.sendto(b'data', ('127.0.0.1', 9001))
      result1 = sock_in1.recvfrom(8)
  
      sock_out.sendto(b'data', ('127.0.0.1', 9002))
      result2 = sock_in2.recvfrom(8)
  
      sock_out.close()
      sock_in1.close()
      sock_in2.close()
  
      # make sure they're from the same source port
      assert result1 == result2
  
      # Test 2: same source port IPv6
      # try again from the same port but IPv6
      sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                  socket.SOL_UDP)
      sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
      sock_out.bind(('127.0.0.1', 9000))
  
      sock_in1 = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM,
                               socket.SOL_UDP)
      sock_in2 = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM,
                               socket.SOL_UDP)
  
      sock_in1.bind(('::1', 9001))
      sock_in2.bind(('::1', 9002))
  
      sock_out.sendto(b'data', ('::1', 9001))
      result1 = sock_in1.recvfrom(8)
  
      sock_out.sendto(b'data', ('::1', 9002))
      result2 = sock_in2.recvfrom(8)
  
      sock_out.close()
      sock_in1.close()
      sock_in2.close()
  
      # make sure they're from the same source port
      assert result1 == result2
  
      # Test 3: different source ports IPv6
      sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                  socket.SOL_UDP)
      sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
      sock_out.bind(('127.0.0.1', 9003))
  
      sock_in1 = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM,
                               socket.SOL_UDP)
      sock_in1.bind(('::1', 9001))
      sock_out.sendto(b'data', ('::1', 9001))
      result3 = sock_in1.recvfrom(8)
  
      # make sure they're from different source ports
      assert result1 != result3
  
      sock_out.close()
      sock_in1.close()
  
subject: add test_udp_src