docs: function(cell) {
      cellsize = cell || 64;
      this.map = {};
  
      this.boundsDirty = false;
      this.coordBoundsDirty = false;
      this.boundsHash = {
          maxX: -Infinity,
          maxY: -Infinity,
          minX: Infinity,
          minY: Infinity
      };
      this.boundsCoords = {
          maxX: -Infinity,
          maxY: -Infinity,
          minX: Infinity,
          minY: Infinity
      };
  }