code: function(callback) {
        var asyncFunctions = [];
  
        for (var i = 0; i < numberOfRows; i++) {
          var rowsImagesPaths = imagesPaths.slice(i * numberOfColumns, i * numberOfColumns + numberOfColumns);
          var lineWidth = width;
          var lineHeight = height;
          var linePath = path.join(temporaryDirectoryPath, 'line-' + i);
  
          linesPaths.push(linePath);
          asyncFunctions.push(createLine(rowsImagesPaths, linePath, lineWidth, lineHeight, true, 100));
        }
  
        async.parallel(asyncFunctions, function(error, results) {
          if (error) return callback(error);
  
          results.forEach(function(line) {
            line.forEach(function(image) {
              if (image.image === path.join(temporaryDirectoryPath, 'transparent.png')) return;
  
              var spritePathChunks = path.parse(image.sprite).name.match(/-([0-9]+)$/);
              var lineIndex = (spritePathChunks && parseInt(spritePathChunks[1])) || 0;
  
              image.y = image.y + (lineIndex * height);
              image.sprite = destinationPath;
              images.push(image);
            });
          });
  
          callback();
        });
      }
docs: Create sprite horizontal lines