public async Task AddDocument_NewDocument_ReturnsNullOkObjectResult()
{
// Arrange
RegionDocumentDTO document = new RegionDocumentDTO();
// Act
var result = await _regionController.AddDocument(document);
_logger.Setup(x => x.LogInformation(It.IsAny <string>()));
var actual = (result as ObjectResult).Value;
// Assert
Assert.IsInstanceOf <OkObjectResult>(result);
Assert.IsInstanceOf <RegionDocumentDTO>(actual);
}