code: def __iter__(self):
      buf = self._fill_buf()
      if buf is not None:
          for line in buf:
              if line.endswith(b"\n"):
                  yield line
              else:
                  self._tail = line
                  break
  
file_path: metaflow/metaflow/plugins/datatools/s3/s3tail.py
imports: from io import BytesIO
  from .s3util import aws_retry, get_s3_client
label_desc: Use image node_id 6 for calling the S3Tail obj's underlying member method code with example usage: obj.__iter__() without return types