responseType
Returns the response type.
Can be set to change the response type. Values are: the empty string (default), "arraybuffer", "blob", "document", "json", and "text".
When set: setting to "document" is ignored if current global object is not a Window object.
When set: throws an "InvalidStateError" DOMException if state is loading or done.
When set: throws an "InvalidAccessError" DOMException if the synchronous flag is set and current global object is a Window object.