code: def parse_int(self, buff, start, end):
          '''
              parse an integer from the buffer given the interval of bytes
          :param buff:
          :param start:
          :param end:
          '''
  #         num = self.parse_uint(buff, start, end)
  #         l = (end - start)
  #         return self.twos_comp(num, l * 8)
          return struct.unpack_from(self.structmap[end - start], buff, start)[0f parse_int(self, buff, start, end):
          '''
              parse an integer from the buffer given the interval of bytes
          :param buff:
          :param start:
          :param end:
          '''
  #         num = self.parse_uint(buff, start, end)
  #         l = (end - start)
  #         return self.twos_comp(num, l * 8)
          return struct.unpack_from(self.structmap[end - start], buff, start)[0]
docs: parse an integer from the buffer given the interval of bytes
          :param buff:
          :param start:
          :param end: