public void OpenConnection_CreateProviderWithConnectionAndOpenIt_ReturnsUnderlyingOpenedConnection() {
var provider = A.Fake<IProvider>();
var underlyingConnection = A.Fake<IDbConnection>();
A.CallTo(() => provider.CreateConnection()).Returns(underlyingConnection);
var dataSource = new DataSource(provider);
var connection = dataSource.OpenConnection();
A.CallTo(() => underlyingConnection.Open()).MustHaveHappened(Repeated.Exactly.Once);
Assert.AreEqual(underlyingConnection, connection);
}