@DisplayName("Test haveCapability with multiple capability flags")
    void testHaveCapabilityMultipleFlags() {
        // Arrange
        int cap1 = 0x00000001;
        int cap2 = 0x00000002;
        int cap3 = 0x00000004;
        when(negotiationResponse.haveCapabilitiy(cap1)).thenReturn(true);
        when(negotiationResponse.haveCapabilitiy(cap2)).thenReturn(false);

	for i := 0; i < 5<<10; i++ {
		b.Write(buf)
		b.Read(buf)
		if i == 0 {
			cap0 = b.Cap()
		}
	}
	cap1 := b.Cap()
	// (*Buffer).grow allows for 2x capacity slop before sliding,
	// so set our error threshold at 3x.
	if cap1 > cap0*3 {
		t.Errorf("buffer cap = %d; too big (grew from %d)", cap1, cap0)
	}
}

func BenchmarkWriteByte(b *testing.B) {
	const n = 4 << 10
	b.SetBytes(n)