code: def run_step(context):
      
      logger.debug("started")
      deprecated(context)
  
      StreamRewriterStep(__name__, 'fileFormat', context).run_step()
  
      logger.debug("done")
docs: Parse input file and substitutes {tokens} from context.
  
      Args:
          context: pypyr.context.Context. Mandatory.
                   The following context keys expected:
                  - fileFormat
                      - in. mandatory.
                        str, path-like, or an iterable (list/tuple) of
                        strings/paths. Each str/path can be a glob, relative or
                        absolute path.
                      - out. optional. path-like.
                        Can refer to a file or a directory.
                        will create directory structure if it doesn't exist. If
                        in-path refers to >1 file (e.g it's a glob or list), out
                        path can only be a directory - it doesn't make sense to
                        write >1 file to the same single file (this is not an
                        appender.) To ensure out_path is read as a directory and
                        not a file, be sure to have the path separator (/) at the
                        end.
                        If out_path is not specified or None, will in-place edit
                        and overwrite the in-files.
  
      Returns:
          None.
  
      Raises:
          FileNotFoundError: take a guess
          pypyr.errors.KeyNotInContextError: fileFormat missing in context.
          pypyr.errors.KeyInContextHasNoValueError: in or out exists but is None.