code: function (sector, level, row, column) {
              Tile.call(this, sector, level, row, column); // args are checked in the superclass' constructor
  
              /**
               * The transformation matrix that maps tile local coordinates to model coordinates.
               * @type {Matrix}
               */
              this.transformationMatrix = Matrix.fromIdentity();
  
              /**
               * The tile's model coordinate points.
               * @type {Float32Array}
               */
              this.points = null;
  
              /**
               * Indicates the state of this tile when the model coordinate points were last updated. This is used to
               * invalidate the points when this tile's state changes.
               * @type {String}
               */
              this.pointsStateKey = null;
  
              /**
               * Indicates the state of this tile when the model coordinate VBO was last uploaded to GL. This is used to
               * invalidate the VBO when the tile's state changes.
               * @type {String}
               */
              this.pointsVboStateKey = null;
  
              // Internal use. Intentionally not documented.
              this.neighborMap = {};
              this.neighborMap[WorldWind.NORTH] = null;
              this.neighborMap[WorldWind.SOUTH] = null;
              this.neighborMap[WorldWind.EAST] = null;
              this.neighborMap[WorldWind.WEST] = null;
  
              // Internal use. Intentionally not documented.
              this._stateKey = null;
  
              // Internal use. Intentionally not documented.
              this._elevationTimestamp = null;
  
              // Internal use. Intentionally not documented.
              this.scratchArray = [];
          }
docs: Constructs a terrain tile.
  @alias TerrainTile
  @constructor
  @augments Tile
  @classdesc Represents a portion of a globe's terrain. Applications typically do not interact directly with
  this class.
  @param {Sector} sector The sector this tile covers.
  @param {Level} level The level this tile is associated with.
  @param {Number} row This tile's row in the associated level.
  @param {Number} column This tile's column in the associated level.
  @throws {ArgumentError} If the specified sector or level is null or undefined or the row or column arguments
  are less than zero.