class RuboCop::Cop::Style::CommentAnnotation

def correct_annotation?(first_word, colon, space, note)
  keyword?(first_word) && (colon && space && note || !colon && !note)
end

def investigate(processed_source)
  processed_source.comments.each do |comment|
    margin, first_word, colon, space, note = split_comment(comment)
    next unless annotation?(comment) &&
                !correct_annotation?(first_word, colon, space, note)
    start = comment.loc.expression.begin_pos + margin.length
    length = first_word.length + (colon || '').length
    range = Parser::Source::Range.new(processed_source.buffer,
                                      start,
                                      start + length)
    add_offense(nil, range)
  end
end