class Fluent::LogDeviceIO

github.com/ruby/ruby/blob/7b2d47132ff8ee950b0f978ab772dee868d9f1b0/lib/logger.rb#L661<br>This class delegetes some methods which are used in ‘Fluent::Logger` to a instance variable(`dev`) in `Logger::LogDevice` class

def flush
  if @dev.respond_to?(:flush)
    @dev.flush
  else
    super
  end
end

def reopen(path, mode)
  if mode != 'a'
    raise "Unsupported mode: #{mode}"
  end
  super(path)
end

def sync=(v)
  if @dev.respond_to?(:sync=)
    @dev.sync = v
  else
    super
  end
end

def tty?
  if @dev.respond_to?(:tty?)
    @dev.tty?
  else
    super
  end
end

Modules