code: private GenericScanner2 getSpiderScan(JSONObject params) throws ApiException {
  		GenericScanner2 spiderScan;
  		int id = getParam(params, PARAM_SCAN_ID, -1);
  		if (id == -1) {
  			spiderScan = extension.getLastScan();
  		} else {
  			spiderScan = extension.getScan(id);
  		}
  
  		if (spiderScan == null) {
  			throw new ApiException(ApiException.Type.DOES_NOT_EXIST, PARAM_SCAN_ID);
  		}
  
  		return spiderScan;
  	}
docs: Returns the specified GenericScanner2 or the last scan available.
  
  @param params the parameters of the API call
  @return the GenericScanner2 with the given scan ID or, if not present, the last scan available
  @throws ApiException if there's no scan with the given scan ID
  @see #PARAM_SCAN_ID