```ruby
module Zuora
  class HttpClient
    include HTTParty

    format  :json
    headers "Accept" => "application/json"
    headers "Content-Type" => "application/json"
  end
end
```

Add a user agent to API requests
user
```ruby
module Zuora
  class HttpClient
    include HTTParty

    format  :json
    headers "Accept" => "application/json"
    headers "Content-Type" => "application/json"
    headers "User-Agent" => "zuora-rest/#{Zuora::VERSION}"
  end
end
```
assistant