func (bp *BytePoolCap) Put(b []byte) {
	if bp == nil {
		return
	}
	select {
	case bp.c <- b:
		// buffer went back into pool
	default:
		// buffer didn't go back into pool, just discard
	}
}

// Width returns the width of the byte arrays in this pool.
func (bp *BytePoolCap) Width() (n int) {
	if bp == nil {
		return 0
	}
	return bp.w
}

	if m == nil {
		return false
	}
	cache := m
	switch {
	case !cache.finished() && time.Since(cache.lastUpdate) > metacacheMaxRunningAge:
		// Not finished and update for metacacheMaxRunningAge, discard it.
		return false
	case cache.finished() && time.Since(cache.lastHandout) > 5*metacacheMaxClientWait:
		// Keep for 15 minutes after we last saw the client.

	}
}

func TestCloseOnWriter(t *testing.T) {
	writer := WriteOnClose(io.Discard)
	if writer.HasWritten() {
		t.Error("WriteOnCloser must not be marked as HasWritten")
	}
	writer.Write(nil)
	if !writer.HasWritten() {
		t.Error("WriteOnCloser must be marked as HasWritten")
	}

	writer = WriteOnClose(io.Discard)
	writer.Close()
	if !writer.HasWritten() {
		t.Error("WriteOnCloser must be marked as HasWritten")