docs: @RequestMapping(value="/{subscription}", method=POST)
  	public @ResponseBody String receiveUpdate(
  			@PathVariable("subscription") String subscription,
  			@RequestBody String payload,
  			@RequestHeader(X_HUB_SIGNATURE) String signature) throws Exception {
  
  		// Can only read body once and we need it as a raw String to calculate the signature.
  		// Therefore, use Jackson ObjectMapper to give us a RealTimeUpdate object from that raw String.
  		RealTimeUpdate update = new ObjectMapper().readValue(payload, RealTimeUpdate.class);		
  		if (verifySignature(payload, signature)) {
  			logger.debug("Received " + update.getObject() + " update for '" + subscription + "'.");
  			for (UpdateHandler handler : updateHandlers) {
  				handler.handleUpdate(subscription, update);
  			}
  		} else {
  			logger.warn("Received an update, but signature was invalid. Not delegating to handlers.");
  		}
  		return "";
  	}