func TestCommonParities(t *testing.T) {
	// This test uses two FileInfo values that represent the same object but
	// have different parities. They occur in equal number of drives, but only
	// one has read quorum. commonParity should pick the parity corresponding to
	// the FileInfo which has read quorum.
	fi1 := FileInfo{
		Volume:         "mybucket",
		Name:           "myobject",
		VersionID:      "",
		IsLatest:       true,