old_contents: 
  import unittest
  import binascii
  import difflib
  import struct
  import array
  
  import Xlib.protocol.event
  import Xlib.protocol.rq
  
  
  class CmpArray(object):
  
      def __init__(self, *args, **kws):
          self.array = array.array(*args, **kws)
  
      def __len__(self):
          return len(self.array)
  
      def __getitem__(self, key):
          if isinstance(key, slice):
              x = key.start
              y = key.stop
              return list(self.array[x:y])
          else:
              return self.array[key]
  
      def __getattr__(self, attr):
          return getattr(self.array, attr)
  
      def __eq__(self, other):
          return self.array.tolist() == other
  
  Xlib.protocol.rq.array = CmpArray
  
  
  class DummyDisplay(object):
  
      def get_resource_class(self, x):
          return None
  
      event_classes = Xlib.protocol.event.event_class
  
  
  class TestCase(unittest.TestCase):
  
      def assertBinaryEqual(self, bin1, bin2):
          if bin1 != bin2:
              self.fail('binary contents differ:\n' + bindiff(bin1, bin2))
  
      def assertBinaryEmpty(self, bin):
          if len(bin) != 0:
              self.fail('binary content not empty:\n' + ''.join(tohex(bin)))
  
  class BigEndianTest(TestCase):
  
      @classmethod
      def setUpClass(cls):
          if struct.unpack('BB', struct.pack('H', 0x0100))[0] != 1:
              raise unittest.SkipTest('big-endian tests, skipping on this system')
  
  class LittleEndianTest(TestCase):
  
      @classmethod
      def setUpClass(cls):
          if struct.unpack('BB', struct.pack('H', 0x0100))[0] != 0:
              raise unittest.SkipTest('little-endian tests, skipping on this system')
  
  
  def tohex(bin):
      hex = []
      for i in range(0, len(bin), 16):
          hex.append(binascii.hexlify(bin[i:i+16]) + '\n')
      return hex
  
  def bindiff(bin1, bin2):
      hex1 = tohex(bin1)
      hex2 = tohex(bin2)
      return ''.join(difflib.ndiff(hex1, hex2))
  
new_contents: 
  import unittest
  import binascii
  import difflib
  import struct
  import array
  
  import Xlib.protocol.event
  import Xlib.protocol.rq
  
  
  class CmpArray(object):
  
      def __init__(self, *args, **kws):
          self.array = array.array(*args, **kws)
  
      def __len__(self):
          return len(self.array)
  
      def __getitem__(self, key):
          if isinstance(key, slice):
              x = key.start
              y = key.stop
              return list(self.array[x:y])
          else:
              return self.array[key]
  
      def __getattr__(self, attr):
          return getattr(self.array, attr)
  
      def __eq__(self, other):
          return self.array.tolist() == other
  
  Xlib.protocol.rq.array = CmpArray
  
  
  class DummyDisplay(object):
  
      def get_resource_class(self, x):
          return None
  
      event_classes = Xlib.protocol.event.event_class
  
  
  class TestCase(unittest.TestCase):
  
      def assertBinaryEqual(self, bin1, bin2):
          if bin1 != bin2:
              self.fail('binary contents differ:\n' + bindiff(bin1, bin2))
  
      def assertBinaryEmpty(self, bin):
          if len(bin) != 0:
              self.fail('binary content not empty:\n' + ''.join(tohex(bin)))
  
  class BigEndianTest(TestCase):
  
      @classmethod
      def setUpClass(cls):
          if struct.unpack('BB', struct.pack('H', 0x0100))[0] != 1:
              raise unittest.SkipTest('big-endian tests, skipping on this system')
  
  class LittleEndianTest(TestCase):
  
      @classmethod
      def setUpClass(cls):
          if struct.unpack('BB', struct.pack('H', 0x0100))[0] != 0:
              raise unittest.SkipTest('little-endian tests, skipping on this system')
  
  
  def tohex(bin):
      hex = []
      for i in range(0, len(bin), 16):
          hex.append(str(binascii.hexlify(bin[i:i+16])) + '\n')
      return hex
  
  def bindiff(bin1, bin2):
      hex1 = tohex(bin1)
      hex2 = tohex(bin2)
      return ''.join(difflib.ndiff(hex1, hex2))
  
subject: fix tohex helper