code: def write_bytes(self, data: bytes, *, append=True):
          ''' write bytes into the file. '''
          mode = 'ab' if append else 'wb'
          return self.write(data, mode=modef write_bytes(self, data: bytes, *, append=True):
          ''' write bytes into the file. '''
          mode = 'ab' if append else 'wb'
          return self.write(data, mode=mode)
docs: write bytes into the file.