Test for null settings sent to client options

Author: dylan-asos

tests/SendGrid.Tests/Reliability/ReliabilitySettingsTests.cs

@@ -101,6 +101,14 @@ public void ShouldPassValidValuesFromDefaultConstruct()
             Assert.Equal(TimeSpan.Zero, defaultSettings.DeltaBackOff);
             Assert.Equal(0, defaultSettings.MaximumNumberOfRetries);
         }
+
+        [Fact]
+        public void ShouldNotAllowNullInstanceOnSendGridClientOptions()
+        {
+            var options = new SendGridClientOptions();
+
+            Assert.Throws<ArgumentNullException>(() => options.ReliabilitySettings = null);
+        }
     }
 }