code: def read_int64(self, little_endian=True):
          
          if little_endian:
              endian = "<"
          else:
              endian = ">"
          return self.unpack('%sq' % endian, 8)
docs: Read 8 bytes as a signed integer value from the stream.
  
          Args:
              little_endian (bool): specify the endianness. (Default) Little endian.
  
          Returns:
              int: