# File lib/mspec/runner/mspec.rb, line 306
306:   def self.write_tag(tag)
307:     string = tag.to_s
308:     file = tags_file
309:     path = File.dirname file
310:     FileUtils.mkdir_p path unless File.exist? path
311:     if File.exist? file
312:       File.open(file, "rb") do |f|
313:         f.each_line { |line| return false if line.chomp == string }
314:       end
315:     end
316:     File.open(file, "ab") { |f| f.puts string }
317:     return true
318:   end