fix

Duffel.ApiClient.Tests/ApiClientTests.cs

@@ -1,24 +1,28 @@
-using NFluent;
-using NUnit.Framework;
-
 namespace Duffel.ApiClient.Tests
 {
     using System;
+    using NUnit.Framework;
 
     public class DuffelApiClientTests
     {
         [Test]
         public void ThrowsArgumentExceptionIfAccessTokenIsEmpty()
         {
-            var exception = Assert.Catch<ArgumentException>(() => new DuffelApiClient(String.Empty));
-            Assert.AreEqual("No access token provided. To create an access token, head to your dashboard at https://app.duffel.com/duffel/tokens and generate a token. (Parameter 'accessToken')", exception?.Message);
+            var exception = Assert.Catch<ArgumentException>(() => new DuffelApiClient(string.Empty));
+            Assert.That(
+                "No access token provided. To create an access token, head to your dashboard at https://app.duffel.com/duffel/tokens and generate a token. (Parameter 'accessToken')",
+                Is.EqualTo(exception?.Message)
+            );
         }
 
         [Test]
         public void ThrowsArgumentExceptionIfAccessTokenIsNull()
         {
             var exception = Assert.Catch<ArgumentException>(() => new DuffelApiClient(null));
-            Assert.AreEqual("No access token provided. To create an access token, head to your dashboard at https://app.duffel.com/duffel/tokens and generate a token. (Parameter 'accessToken')", exception?.Message);
+            Assert.That(
+                "No access token provided. To create an access token, head to your dashboard at https://app.duffel.com/duffel/tokens and generate a token. (Parameter 'accessToken')",
+                Is.EqualTo(exception?.Message)
+            );
         }
     }
-}
+}