Wrong keyword in Introduce Local Extension refactoring

Hello,

While learning about Introduce Local Extension refactoring I have found a mistake in the description. I have selected C# as my programming language of choice and the description contains 'final' keyword which is pertaining to Java. C# keyword to prohibit inheritance/overriding is 'sealed'.

Here is a link to the course page: https://refactoring.guru/course/slides/introduce-local-extension/3/

Can you please correct this mistake?

P.S. Feel free to point me to the relevant topic if I should not create separate ones for cases like this.