old_contents: # Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  import dns.rdtypes.sigbase
  
  class SIG(dns.rdtypes.sigbase.SIGBase):
      """SIG record"""
      def to_digestable(self, origin = None):
          return struct.pack('!HBBIIIH', self.type_covered,
                             self.algorithm, self.labels,
                             self.original_ttl, self.expiration,
                             self.inception, self.key_tag) + \
                             self.signer.to_digestable(origin) + \
                             self.signature
      def _cmp(self, other):
          hs = struct.pack('!HBBIIIH', self.type_covered,
                           self.algorithm, self.labels,
                           self.original_ttl, self.expiration,
                           self.inception, self.key_tag)
          ho = struct.pack('!HBBIIIH', other.type_covered,
                           other.algorithm, other.labels,
                           other.original_ttl, other.expiration,
                           other.inception, other.key_tag)
          v = cmp(hs, ho)
          if v == 0:
              v = cmp(self.signer, other.signer)
              if v == 0:
                  v = cmp(self.signature, other.signature)
          return v
  
new_contents: # Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  import struct
  
  import dns.rdtypes.sigbase
  
  class SIG(dns.rdtypes.sigbase.SIGBase):
      """SIG record"""
      def to_digestable(self, origin = None):
          return struct.pack('!HBBIIIH', self.type_covered,
                             self.algorithm, self.labels,
                             self.original_ttl, self.expiration,
                             self.inception, self.key_tag) + \
                             self.signer.to_digestable(origin) + \
                             self.signature
      def _cmp(self, other):
          hs = struct.pack('!HBBIIIH', self.type_covered,
                           self.algorithm, self.labels,
                           self.original_ttl, self.expiration,
                           self.inception, self.key_tag)
          ho = struct.pack('!HBBIIIH', other.type_covered,
                           other.algorithm, other.labels,
                           other.original_ttl, other.expiration,
                           other.inception, other.key_tag)
          v = cmp(hs, ho)
          if v == 0:
              v = cmp(self.signer, other.signer)
              if v == 0:
                  v = cmp(self.signature, other.signature)
          return v
  
subject: add missing "import struct"