map_stubs

# File lib/rubygems/specification.rb, line 788
    def self.map_stubs(dirs, pattern) # :nodoc:
      dirs.flat_map { |dir|
        base_dir = File.dirname dir
        gems_dir = File.join base_dir, "gems"
        gemspec_stubs_in(dir, pattern) { |path| yield path, base_dir, gems_dir }
      }
    end