def with_file_utils(&block)
      Module.new do
        include Mustermann::FileUtils
        define_method(:f, &block)
        private(:f)
        extend self
      end
    end
def with_file_utils(&block)
      Module.new do
        include Mustermann::FileUtils
        define_method(:f, &block)
        private(:f)
        extend self
      end
    end
Create a new version of Mustermann::FileUtils using a different ::FileUtils module.
 @see DryRun
 @!visibility private