code: function IteratorOptions(options) {
    this.keys = true;
    this.values = true;
    this.start = null;
    this.end = null;
    this.gt = false;
    this.lt = false;
    this.keyAsBuffer = true;
    this.valueAsBuffer = true;
    this.reverse = false;
    this.limit = -1;
  
    if (options)
      this.fromOptions(options);
  }
docs: Iterator Options
  @constructor
  @ignore
  @param {Object} options