Used as a base class for any block that needs to do polling of a URL. Not a stand alone block.

• polling_interval: How often url is polled. A new request will be made for every member of queries at the polling_interval.
• retry_interval: When a request fails, wait this many seconds before attempting a retry.
• retry_limit: The maximum number of retries to attempt for each request.
• queries: List of endpoints to poll.
• include_query: If not None, the endpoint for this request, from queries, will be stored in this attribute of the outgoing signal.

• requests

None