code: def readline(self, size=-1):
      # For backwards compatibility, a (slowish) readline().
      def nreadahead():
          # Read to the beginning of the next line
          read_to = min(
              self._get_size() - 1,
              self._current_pos + self._buffer_size - 1,
          )
          buffer = self._bucket.get_object(
              self._key_name, byte_range=(self._current_pos, read_to)
          ).read()
          if not buffer:
              return 1
          n = (buffer.find(b"\n") + 1) or len(buffer)
          if size >= 0:
              n = min(n, size)
          return n
  
      if size is None:
          size = -1
      else:
          try:
              size_index = size.__index__
          except AttributeError:
              raise TypeError(f"{size!r} is not an integer")
          else:
              size = size_index()
      res = bytearray()
      while size < 0 or len(res) < size:
          b = self.read(nreadahead())
          if not b:
              break
          res += b
          if res.endswith(b"\n"):
              break
      return bytes(res)
  
file_path: mars/mars/lib/filesystem/_oss_lib/handle.py
imports: from io import IOBase
  from ....utils import lazy_import
  from .common import parse_osspath, oss_stat
label_desc: Use image node_id 9 for calling the OSSIOBase obj's underlying member method code with example usage: obj.readline(size) and returns: bytes, n, int