1. An apparatus operating on a time sequence of events, the apparatus comprising: an event handling module configured to generate a predicted label for a current observed event of the time sequence of events; and a true label handling module configured to process a true label revealed for an observed event of the time sequence of events; wherein the event handling module and the true label handling module cooperatively model stochastic dependence of a true label for the current observed event based on observed events of the time sequence of events and revealed true labels for past observed events of the time sequence of events; and wherein the event handling module and the true label handling module operate asynchronously; and wherein the event handling module and the true label handling module are embodied by one or more digital processors.