Add project files.

Core.Cerberos.Provider/Providers/BaseProvider.cs

@@ -0,0 +1,16 @@
+using MongoDB.Driver;
+
+namespace Core.Cerberos.Provider.Providers
+{
+    public class BaseProvider
+    {
+        private readonly IMongoDatabase _database;
+
+        public BaseProvider(IMongoDatabase database)
+        {
+            _database = database ?? throw new ArgumentNullException(nameof(database));
+        }
+
+        protected IMongoDatabase Database => _database;
+    }
+}