lib/backoff.js
function Backoff(backoffStrategy) {
    events.EventEmitter.call(this);

    this.backoffStrategy_ = backoffStrategy;
    this.maxNumberOfRetry_ = -1;
    this.backoffNumber_ = 0;
    this.backoffDelay_ = 0;
    this.timeoutID_ = -1;

    this.handlers = {
        backoff: this.onBackoff_.bind(this)
    };
}
function Backoff(backoffStrategy) {
    events.EventEmitter.call(this);

    this.backoffStrategy_ = backoffStrategy;
    this.maxNumberOfRetry_ = -1;
    this.backoffNumber_ = 0;
    this.backoffDelay_ = 0;
    this.timeoutID_ = -1;

    this.handlers = {
        backoff: this.onBackoff_.bind(this)
    };
}
A class to hold the state of a backoff operation. Accepts a backoff strategy to generate the backoff delays.