select @@VERSION

Microsoft SQL Server 2014 - 12.0.2254.0 (X64) 
Jul 25 2014 18:52:51 
Copyright (c) Microsoft Corporation
Developer Edition (64-bit) on Windows NT 6.3 <X64> (Build 9600: )

        protected virtual string ConnectionString
        {
            get
            {
                return (string)DbConnection.GetPrivateFieldValue("_connectionString");
            }
        }

protected virtual string ConnectionString {
  get {
    return (string)DbConnection.ConnectionString;
  }
}