def save(dir = Dir.pwd, options = {})
      prefix = options[:prefix] if options.key?(:prefix)
      write_file(File.join(dir, "#{prefix}#{lang}.yml"), options)
    end
def save(dir = Dir.pwd, options = {})
      prefix = options[:prefix] if options.key?(:prefix)
      write_file(File.join(dir, "#{prefix}#{lang}.yml"), options)
    end
Save the file

 @param dir [String] Directory path to save the file
 @param options [Hash] Options for saving
 @return int