public void GetHttpHeaderValue_HttpRequestHeaderStringFound_HeaderValue()
        {
            //Arrange
            var httpRequest = MockRepository.GenerateMock<HttpRequestBase>();
            var headerDefaultValue = "Unknown User Agent";
            var headerValue = "Talifun Browser";
            var headerType = HttpRequestHeader.UserAgent;
            var headerName = (string)headerType;

            httpRequest.Expect(x => x.Headers[headerName]).Return(headerValue);
   
            //Act
            var httpRequestHeaderHelper = new HttpRequestHeaderHelper();
            var userAgentValue = httpRequestHeaderHelper.GetHttpHeaderValue(httpRequest, headerName, headerDefaultValue);

            //Assert
            httpRequest.VerifyAllExpectations();
            Assert.AreEqual(headerValue, userAgentValue);
        }