Updated for C# 10
MODIFY
src/Chapter01/Chapter01.csproj
src/Chapter01/Chapter01.csproj
unexpected exception as concept to check for null hasn't been explained yet-->
<IgnoredWarnings>$(IgnoredWarnings),CS8600,CA1052,IDE0059,IDE0060</IgnoredWarnings>
<StartupObject>AddisonWesley.Michaelis.EssentialCSharp.Shared.Program</StartupObject>
+ <ImplicitUsings>Enable</ImplicitUsings>
</PropertyGroup>
<Import Project="..\Chapter.props" />
<ItemGroup>

Updated for C# 10