function AStar(toX, toY, passableCallback, options) {
      var _this21;
      if (options === void 0) {
        options = {};
      }
      _this21 = _Path2.call(this, toX, toY, passableCallback, options) || this;
      _this21._todo = [];
      _this21._done = {};
      return _this21;
    }
@class Simplified A* algorithm: all edges have a value of 1
@augments ROT.Path
@see ROT.Path