def find_stylesheet!(name)
      errors = []
      @providers.each do |provider|
        begin
          return provider.find_stylesheet!(name)
        rescue CssNotFound => error
          errors << error
        end
      end
      raise ProvidersFailed.new(name, self, errors)
    end
def find_stylesheet!(name)
      errors = []
      @providers.each do |provider|
        begin
          return provider.find_stylesheet!(name)
        rescue CssNotFound => error
          errors << error
        end
      end
      raise ProvidersFailed.new(name, self, errors)
    end
Tries to find the given stylesheet and raises an {ProvidersFailed} error
 if no provider could find the asset.

 @return [Stylesheet]