def say_warning(*args)
      args.each do |arg|
        say HighLine.default_instance.color(arg, :yellow)
      end
    end
def say_warning(*args)
      args.each do |arg|
        say HighLine.default_instance.color(arg, :yellow)
      end
    end
'Say' something using the WARNING color (yellow).

 === Examples
   say_warning 'This is a warning'
   say_warning 'Be careful', 'Think about it'