code: def bytes_read(self):
      return self._pos
  
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 4 for calling the S3Tail obj's underlying member method code with example usage: obj.bytes_read() and returns: self