Apply a filter to each event (5 times) 3. Add a filtered event to an EventStream object (5times) [e1, e2, e3, e4, e5] If 10 filters are applied 1. call 10 times 2. call 50 times 3. call 50 times [e1’, e2’, e3’, e4’, e5’] [e1x, e2x, e3x, e4x, e5x] Filter n Current filters