Responds to a GET request to /predict/[datum] , or a POST to /predict containing several data points, one on each line. The inputs are data points to predict, delimited, like "1,foo,3.0". The value of the target feature in the input is ignored. The response body contains the result of prediction, one for each input data point, one per line. The result depends on the classifier or regressor -- could be a number or a category name. If JSON output is selected, the result is a JSON list.