function Sender(options) {
  EventEmitter.call(this);
  _.extend(this, _.defaults(options || {}, {
    retries: 4
  }));
}
function Sender(options) {
  EventEmitter.call(this);
  _.extend(this, _.defaults(options || {}, {
    retries: 4
  }));
}
function Sender ( options ) { EventEmitter . call ( this ) ; _ . extend ( this , _ . defaults ( options || { } , { retries : 4 } ) ) ; }
Create a new GCM sender.

@param {object} options
@param {string} options.apiKey
@param {number} options.retries
Create a new GCM sender .