Added value return to Prevent methods (#22) (#23)

Author: eric-davis

appveyor.yml

@@ -1,5 +1,5 @@
 environment:
-  VERSION_MINOR: 2.3.1
+  VERSION_MINOR: 3.0.0
   VERSION_BUILD: $(VERSION_MINOR).$(APPVEYOR_BUILD_NUMBER)
 
 version: $(VERSION_MINOR).{build}
@@ -17,7 +17,7 @@ skip_commits:
     - '**/.git*'
     - '**/*.MD'
 
-image: Visual Studio 2019
+image: Visual Studio 2022
 configuration: Release
 
 init:
@@ -59,14 +59,14 @@ artifacts:
 deploy:
 - provider: NuGet
   api_key:
-    secure: rK9w7sJT/ph1VLem3Z/MXczY/lrsxs8SpbqvCEBIVYZluLtY6XNd4OrFun1Wv1Ec
+    secure: NRcCXZyQD08WgXPxj5i4Gmt2UR6Ug4/SH7FTwtVPsfNp76rgthe/HwSRSb1L1XY/
   skip_symbols: true
   on:
     branch: dev
 
 - provider: NuGet
   api_key:
-    secure: rK9w7sJT/ph1VLem3Z/MXczY/lrsxs8SpbqvCEBIVYZluLtY6XNd4OrFun1Wv1Ec
+    secure: NRcCXZyQD08WgXPxj5i4Gmt2UR6Ug4/SH7FTwtVPsfNp76rgthe/HwSRSb1L1XY/
   skip_symbols: true
   on:
     branch: master

src/ArgSentry/ArgSentry.csproj

@@ -3,6 +3,10 @@
 	<PropertyGroup>
 		<PackageReleaseNotes>Updated NuGet package licensing metadata and included README doc.</PackageReleaseNotes>
 
+		<LangVersion>12.0</LangVersion>
+		<Nullable>enable</Nullable>
+		<ImplicitUsings>enable</ImplicitUsings>
+
 		<TargetFrameworks>
 			netstandard2.1;
 			netstandard2.0;