# File lib/thor.rb, line 106
    def register_klass_file(klass, file = caller[1].split(":")[0])
      unless self == Thor
        superclass.register_klass_file(klass, file)
        return
      end

      file_subclasses = subclass_files[File.expand_path(file)]
      file_subclasses << klass unless file_subclasses.include?(klass)
      subclasses << klass unless subclasses.include?(klass)
    end