idleCallback

A callback to be invoked each time the dispatcher becomes idle (when the number of running calls returns to zero).

Note: The time at which a call is considered idle is different depending on whether it was run asynchronously or synchronously. Asynchronous calls become idle after the onResponse or onFailure callback has returned. Synchronous calls become idle once execute() returns. This means that if you are doing synchronous calls the network layer will not truly be idle until every returned Response has been closed.