[#85] core/container: Implement CheckFormat function

Implement function that conducts sanity checks of the container data.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/core/container/fmt_test.go

@@ -0,0 +1,46 @@
+package container
+
+import (
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/nspcc-dev/neofs-api-go/pkg"
+	"github.com/nspcc-dev/neofs-api-go/pkg/container"
+	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+	"github.com/nspcc-dev/neofs-node/pkg/util/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCheckFormat(t *testing.T) {
+	c := container.New()
+
+	require.Error(t, CheckFormat(c))
+
+	policy := new(netmap.PlacementPolicy)
+	c.SetPlacementPolicy(policy)
+
+	require.Error(t, CheckFormat(c))
+
+	c.SetVersion(pkg.SDKVersion().ToV2())
+
+	require.Error(t, CheckFormat(c))
+
+	wallet, err := owner.NEO3WalletFromPublicKey(&test.DecodeKey(-1).PublicKey)
+	require.NoError(t, err)
+
+	c.SetOwnerID(owner.NewIDFromNeo3Wallet(wallet).ToV2())
+
+	c.SetNonce(nil)
+
+	require.Error(t, CheckFormat(c))
+
+	uid, err := uuid.NewRandom()
+	require.NoError(t, err)
+
+	nonce, _ := uid.MarshalBinary()
+
+	c.SetNonce(nonce)
+
+	require.NoError(t, CheckFormat(c))
+}