code: function tileToBBOX(tile) {
      var e = tile2lon(tile[0] + 1, tile[2]);
      var w = tile2lon(tile[0], tile[2]);
      var s = tile2lat(tile[1] + 1, tile[2]);
      var n = tile2lat(tile[1], tile[2]);
      return [w, s, e, n];
  }
docs: Get the bbox of a tile
  
  @name tileToBBOX
  @param {Array<number>} tile
  @returns {Array<number>} bbox
  @example
  var bbox = tileToBBOX([5, 10, 10])
  //=bbox