text: const utils = {};
  
  utils.flatten = function flatten(arr, out) {
    const ret = (typeof out === 'undefined') ? [] : out;
    for (let i = 0; i < arr.length; i += 1) {
      if (Array.isArray(arr[i])) {
        utils.flatten(arr[i], ret);
      } else {
        ret.push(arr[i]);
      }
    }
    return ret;
  };
  
  utils.unique = function unique(arr) {
    const out = [];
    for (let i = 0; i < arr.length; i += 1) {
      if (arr.indexOf(arr[i]) == i) {
        out.push(arr[i]);
      }
    }
    return out;
  };
  
  utils.deepCopy = function deepCopy(obj) {
    if (!obj) return obj;
    let out;
    if (Array.isArray(obj)) {
      out = [];
      for (let i = 0; i < obj.length; i += 1) {
        out.push(utils.deepCopy(obj[i]));
      }
      return out;
    }
    if (typeof obj === 'object') {
      out = {};
      Object.keys(obj).forEach((key) => {
        out[key] = utils.deepCopy(obj[key]);
      });
      return out;
    }
    return obj;
  };
  
  export default utils;
  