public async Task GetFileBase64_ReturnsString()
{
// Arrange
_regionService.Setup(x => x.DownloadFileAsync(It.IsAny <string>())).ReturnsAsync("file");
// Act
var result = await _regionController.GetFileBase64("file");
var actual = (result as ObjectResult).Value;
// Assert
Assert.IsInstanceOf <OkObjectResult>(result);
Assert.IsInstanceOf <string>(actual);
}