code: func configFileOverride(config *bzzapi.Config, ctx *cli.Context) (*bzzapi.Config, error) {
  	var err error
  
  	//only do something if the -config flag has been set
  	if ctx.GlobalIsSet(SwarmTomlConfigPathFlag.Name) {
  		var filepath string
  		if filepath = ctx.GlobalString(SwarmTomlConfigPathFlag.Name); filepath == "" {
  			utils.Fatalf("Config file flag provided with invalid file path")
  		}
  		var f *os.File
  		f, err = os.Open(filepath)
  		if err != nil {
  			return nil, err
  		}
  		defer f.Close()
  
  		//decode the TOML file into a Config struct
  		//note that we are decoding into the existing defaultConfig;
  		//if an entry is not present in the file, the default entry is kept
  		err = tomlSettings.NewDecoder(f).Decode(&config)
  		// Add file name to errors that have a line number.
  		if _, ok := err.(*toml.LineError); ok {
  			err = errors.New(filepath + ", " + err.Error())
  		}
  	}
  	return config, err
  }
docs: //configFileOverride overrides the current config with the config file, if a config file has been provided