func BenchmarkCrcHash(b *testing.B) {
	cases := []struct {
		key int
	}{
		{16},
		{64},
		{128},
		{256},
		{512},
		{1024},
	}
	for _, testCase := range cases {
		testCase := testCase
		key := randString(testCase.key)
		b.Run("", func(b *testing.B) {
			b.SetBytes(1024)
			b.ReportAllocs()
			b.ResetTimer()
			for i := 0; i < b.N; i++ {
				crcHashMod(key, 16)
			}
		})
	}
}

		remain--
	}

	return *(*string)(unsafe.Pointer(&b))
}

// generate random object name.
func getRandomObjectName() string {
	return randString(16)
}

// generate random bucket name.
func getRandomBucketName() string {
	return randString(60)
}

// construct URL for http requests for bucket operations.