public void WhenPartitionProviderThenCreatesUntypedWrapper()
{
// arrange
var message = new SomeMessage();
var partitionProviderMock = new Mock <Func <SomeMessage, string, int> >();
partitionProviderMock.Setup(x => x(message, "topic1")).Returns(1);
// act
_pb.PartitionProvider(partitionProviderMock.Object);
// assert
var partitionProvider = _ps.GetPartitionProvider();
partitionProvider(message, "topic1").Should().Be(1);
partitionProviderMock.Verify(x => x(message, "topic1"), Times.Once);
}