def to_templates
      raise NotImplementedError, 'template generation not supported' unless respond_to? :to_templates
      @to_templates ||= patterns.inject(['']) { |list, pattern| list.product(pattern.to_templates).map(&:join) }.uniq
    end
def to_templates
      raise NotImplementedError, 'template generation not supported' unless respond_to? :to_templates
      @to_templates ||= patterns.inject(['']) { |list, pattern| list.product(pattern.to_templates).map(&:join) }.uniq
    end
(see Mustermann::Pattern#to_templates)