def each
      Dir["#{path}/[a-z]*"].each do |dir|
        if File.directory?(dir)
          yield Spec.new(File.basename(dir), dir, label)
        end
      end
    end
def each
      Dir["#{path}/[a-z]*"].each do |dir|
        if File.directory?(dir)
          yield Spec.new(File.basename(dir), dir, label)
        end
      end
    end
Yield each eligible subdirectory.