code: func NewCaptureLogger(outputLogger log.Logger, bufferCap channels.BufferCap, passthrough bool) *CaptureLogger {
  	return &CaptureLogger{
  		bufferLogger: NewChannelLogger(bufferCap),
  		outputLogger: outputLogger,
  		passthrough:  passthrough,
  	}
  }
docs: // Capture logger captures output sent to it in a buffer retaining
  // a reference to its output logger (the logger whose input it is capturing).
  // It can optionally pass logs through to the output logger.
  // Because it holds a reference to its output it can also be used to coordinate
  // Flushing of the buffer to the output logger in special circumstances.