feat(*): Add GenerateStreamFromString helper method for testing

UnitTests/Helpers/StreamHelper.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace UnitTests.Helpers
+{
+    public class StreamHelper
+    {
+        public static Stream GenerateStreamFromString(string s)
+        {
+            var stream = new MemoryStream();
+            var writer = new StreamWriter(stream);
+            writer.Write(s);
+            writer.Flush();
+            stream.Position = 0;
+            return stream;
+        }
+    }
+}