Status code: Description
200: OK, request received, everything normal
301: moved permanently
404: Page not found
500: Internal server error
List of HTTP status codes
https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
3xx Redirection
4xx Client Error
5xx Server Error
the request is successful
200
the request is unsuccessful
400
EX
Error 400: Bad Request Bad endtime value "2014-01-02asdfasdf". Valid values are ISO-8601 timestamps. Usage details are available from https://earthquake.usgs.gov/fdsnws/event/1
200 response code -> Proceed with reading input stream and parsing the JSON response
Any other response code -> Return empty string for the JSON response
