code: func (bp *SizedBufferPool) Get() (b *bytes.Buffer) {
  	select {
  	case b = <-bp.c:
  	// reuse existing buffer
  	default:
  		// create new buffer
  		b = bytes.NewBuffer(make([]byte, 0, bp.a))
  	}
  	return
  }
docs: // Get gets a Buffer from the SizedBufferPool, or creates a new one if none are
  // available in the pool. Buffers have a pre-allocated capacity.