def all_girls(arg = Time.current)
      date = to_date(arg)

      unless @all_girls
        @all_girls = []
        Rubicure::Girl.names.each do |girl_name|
          @all_girls << Rubicure::Girl.find(girl_name)
        end

        @all_girls.uniq!(&:human_name)
      end

      @all_girls.select {|girl| girl.created_date && girl.created_date <= date }
    end
def all_girls(arg = Time.current)
      date = to_date(arg)

      unless @all_girls
        @all_girls = []
        Rubicure::Girl.names.each do |girl_name|
          @all_girls << Rubicure::Girl.find(girl_name)
        end

        @all_girls.uniq!(&:human_name)
      end

      @all_girls.select {|girl| girl.created_date && girl.created_date <= date }
    end
Get all precures

 @param [Time,Date] arg Time, Date or date like String (ex. "2013-12-16")

 @return [Array<Rubicure::Girl>] all precures

 @example
   Precure.all_girls.count
   Precure.all_girls.map(&:precure_name)
   # returns current precure count and names

   Precure.all_girls("2013-10-26").count
   #=> 33

   Precure.all_girls.include?(Cure.echo)
   #=> true