code: function concatAllArray(array) {
    var ret = [];
    for (var ii = 0; ii < array.length; ii++) {
      var value = array[ii];
      if (Array.isArray(value)) {
        push.apply(ret, value);
      } else if (value != null) {
        throw new TypeError(
          'concatAllArray: All items in the array must be an array or null, ' +
          'got "' + value + '" at index "' + ii + '" instead'
        );
      }
    }
    return ret;
  }
docs: Concats an array of arrays into a single flat array.
  
  @param {array} array
  @return {array}