code: function parseFormat(index, args, formatOptions) {
  	let nextValue = args.getNextValue(index);
  	if(nextValue != null) {
  		formatOptions.style = getFormat(nextValue);
  		return index + 2;
  	}
  	
  	throw new Error('No format provided');
  }
docs: Parses the format flag.
  @param The index