```ruby
class Premailer
  module Rails
    module CSSLoaders
      module NetworkLoader
        extend self

        def load(url)
          uri = uri_for_url(url)
          Net::HTTP.get(uri) if uri
        end

        def uri_for_url(url)
          uri = URI(url)

          if uri.host.present?
            return uri if uri.scheme.present?
            URI("http:#{uri}")
          elsif asset_host_present?
            scheme, host = asset_host(url).split(%r{:?//})
            scheme, host = host, scheme if host.nil?
            scheme = 'http' if scheme.blank?
            path = url
            URI(File.join("#{scheme}://#{host}", path))
          end
        end

        def asset_host_present?
          ::Rails.respond_to?(:configuration) &&
            ::Rails.configuration.action_controller.asset_host.present?
        end

        def asset_host(url)
          config = ::Rails.configuration.action_controller.asset_host
          config.respond_to?(:call) ? config.call(url) : config
        end
      end
    end
  end
end
```

Add Accept header to requests in NetworkLoader
user
```ruby
class Premailer
  module Rails
    module CSSLoaders
      module NetworkLoader
        extend self

        def load(url)
          uri = uri_for_url(url)
          Net::HTTP.get(uri, { 'Accept' => 'text/css' }) if uri
        end

        def uri_for_url(url)
          uri = URI(url)

          if uri.host.present?
            return uri if uri.scheme.present?
            URI("http:#{uri}")
          elsif asset_host_present?
            scheme, host = asset_host(url).split(%r{:?//})
            scheme, host = host, scheme if host.nil?
            scheme = 'http' if scheme.blank?
            path = url
            URI(File.join("#{scheme}://#{host}", path))
          end
        end

        def asset_host_present?
          ::Rails.respond_to?(:configuration) &&
            ::Rails.configuration.action_controller.asset_host.present?
        end

        def asset_host(url)
          config = ::Rails.configuration.action_controller.asset_host
          config.respond_to?(:call) ? config.call(url) : config
        end
      end
    end
  end
end
```
assistant