This method is called from the
response object. It sets the content type for the HTTP response.
When developing applications that interact with OrientDB through the HTTP protocol, you may find it useful to set the content type in the responses. This allows you to tell your application how you want it to handle the return content, ensuring that it in turn passes say XML or JSON data to the appropriate parsers.
var obj = response.setContentType(<type>)
<type>Defines the content type you want to set, as a string.
This method returns the updated response object.