NewBalancer creates a new instance of Balancer that needs to balance load between 'workerCount' workers .

NewWorker creates a new instance of the worker with the given work channel size.

Balancer is a type that can balance load among a set of workers .

Pool is the collection of Worker, it is a min-heap that implements heap.Interface.

Request represents a work that Worker needs to execute .

Worker represents a type which can listen for work from a channel and run them .