int getClassId(final @NotNull ObjectStubSerializer<?, ? extends Stub> serializer) {
    Integer idValue = mySerializerToId.get(serializer);
    if (idValue == null) {
      String name = serializer.getExternalId();
      idValue = myNameToId.getInt(name);
      assert idValue > 0 : "No ID found for serializer " + objectInfo(serializer) + ", external id:" + name +
                           (serializer instanceof IElementType ? ", language:" + ((IElementType)serializer).getLanguage() : "");
      mySerializerToId.put(serializer, idValue);
    }
    return idValue;
  }
int getClassId(final @NotNull ObjectStubSerializer<?, ? extends Stub> serializer)