C#: Examples of lambda expressions with explicit return types.

Author: michaelnebel

csharp/ql/test/library-tests/csharp10/Lambda.cs

@@ -4,8 +4,17 @@ public class Lambda
 {
     public void M1()
     {
+        // Examples need for implicitly typed lambdas.
         Func<int, string> f1 = (int x) => x.ToString();
         var f2 = (int x) => x.ToString();
+
+        // Examples need for  explicit return type for implicitly and explicitly typed lambda.
+        var f3 = object (bool b) => b ? "1" : 0;
+        Func<bool, object> f4 = object (bool b) => b ? "1" : 0;
+
+        // Examples needed for explicit return type for downcast.
+        var f5 = int (bool b) => b ? 1 : 0;
+        var f6 = object (bool b) => b ? 1 : 0;
     }
 }