module.exports = function()

in src/utils/union.js [8:20]


module.exports = function(arrays) {
  const result = new Set(arrays[0]);

  let i,j, array;
  for (i = 1; i < arrays.length; i++) {
    array = arrays[i];
    for (j = 0; j < array.length; j++) {
      result.add(array[j]);
    }
  }

  return Array.from(result);
};