code: function Queue(customConfig){
  	// Allow the class to be called as a function, returning an instance
  	if(!(this instanceof Queue)){
          return new Queue(customConfig);
  	}
  	// Set the default configuration
  	this.config = util.merge({}, defaultConfig);
  	if(customConfig && (typeof customConfig === 'object')){
  		this.setConfig(customConfig);
  	}
  	this._stack = [];
  	this._firstCall = 0;
  	this._callCount = 0;
  }
docs: Object constructor
  @param {object} [customConfig] - Optional custom configuration object
  @returns {Queue}