This example demonstrates a very basic proof-of-concept of how to adapt ExtJS framework to use flXHR instead of its other XHR (and workaround) methods. The basic concept is that ExtJS has a "factory" function which gives it a new XHR object to use for each request. If you overwrite the default ExtJS method with a function that instead instantiates a new flXHR object (or returns an existing reusable one) each time, then ExtJS will not know the difference, because flXHR is compatible with the native XHR API. This example is by no means a "best practice" on how to integrate flXHR with ExtJS, as there may be other efficient ways of accomplishing the integration tasks.
Each successive click of the button will fire off twice as many concurrent requests as the previous click, to demonstrate how the "instancePooling" feature re-uses previous instances when available.