public override void RemoveView(IdentKey key)
        {
            base.RemoveView(key);
            BaseDocument document = GetDocumentByIdentKey(key);

            if (document == null)
            {
                throw new InvalidOperationException("View's document with such key is not find.");
            }
            if (document.IsFloating)
            {
                _documentManager.View.FloatDocuments.Remove(document);
            }
            else
            {
                _documentManager.View.Documents.Remove(document);
            }
            document.Dispose();
            _views.Remove(key);
        }