public class MyBaseClass
    {
        public MyBaseClass() {}
    }

    public sealed class MyClass : MyBaseClass
    {
        // Original: The usage of base-keyword is not valid in this context
        // Better: can't use base-keyword with => operator did you mean ": base()" - call
        public MyClass() => base() {}

        // Original: method name expected
        // Better: can't use this-keyword with => operator did you mean ": this()" - call
        public MyClass() => this() {}
    }