def save(self, output_file=None, 
                   convert_to=None, 
                   runscript="/bin/bash",
                   force=False):

        '''save will convert a recipe to a specified format (defaults to the
           opposite of the recipe type originally loaded, (e.g., docker-->
           singularity and singularity-->docker) and write to an output file,
           if specified. If not specified, a temporary file is used.

           Parameters
           ==========
           output_file: the file to save to, not required (estimates default)
           convert_to: can be manually forced (docker or singularity)
           runscript: default runscript (entrypoint) to use
           force: if True, override discovery from Dockerfile

        '''

        converted = self.convert(convert_to, runscript, force)
        if output_file is None:
            output_file = self._get_conversion_outfile(convert_to=None)
        bot.info('Saving to %s' %output_file)
        write_file(output_file, converted)
save will convert a recipe to a specified format (defaults to the
           opposite of the recipe type originally loaded, (e.g., docker-->
           singularity and singularity-->docker) and write to an output file,
           if specified. If not specified, a temporary file is used.

           Parameters
           ==========
           output_file: the file to save to, not required (estimates default)
           convert_to: can be manually forced (docker or singularity)
           runscript: default runscript (entrypoint) to use
           force: if True, override discovery from Dockerfile