code: def seek(self, offset, whence=0):
          
          assert offset == 0
          self.linepos = 0
          return self.stream.seek(offset, whence)
docs: seek(offset[, whence]) -> None.  Move to new file position.
  
          Argument offset is a byte count.  Optional argument whence defaults to
          0 (offset from start of file, offset should be >= 0); other values are 1
          (move relative to current position, positive or negative), and 2 (move
          relative to end of file, usually negative, although many platforms allow
          seeking beyond the end of a file).  If the file is opened in text mode,
          only offsets returned by tell() are legal.  Use of other offsets causes
          undefined behavior.
          Note that not all file objects are seekable.