1. A method, in a data processing system having a processor and a memory, wherein the memory comprises instructions which are executed by the processor to cause the processor to implement a stream computing platform for data stream change detection and model swapping, the method comprising: building, by a machine learning component executing within the stream computing platform, a model for each input data stream in the stream computing platform, wherein each tuple of each given input data stream is tagged with a key corresponding to the given input data stream; performing, by an operator component executing within the stream computing platform, an operation on each input data stream using its corresponding model; detecting, by a change detection component executing within the stream computing platform, a misdirected input data stream, wherein the misdirected input data stream is tagged with a key that does not correspond to the misdirected input data stream; pausing, by the change detection component, the misdirected input data stream; and swapping, by a model swapping component executing within the stream computing platform, a model corresponding to the misdirected input data stream with another model corresponding to another paused input data stream.