DotObject.prototype._fill = function (a, obj, v, mod) {
  var k = a.shift()

  if (a.length > 0) {
    obj[k] = obj[k] ||
      (this.useArray && isIndex(a[0]) ? [] : {})

    if (!isArrayOrObject(obj[k])) {
      if (this.override) {
        obj[k] = {}
      } else {
        if (!(isArrayOrObject(v) && isEmptyObject(v))) {
          throw new Error(
            'Trying to redefine `' + k + '` which is a ' + typeof obj[k]
          )
        }

        return
      }
    }

    this._fill(a, obj[k], v, mod)
  } else {
    if (!this.override &&
      isArrayOrObject(obj[k]) && !isEmptyObject(obj[k])) {
      if (!(isArrayOrObject(v) && isEmptyObject(v))) {
        throw new Error("Trying to redefine non-empty obj['" + k + "']")
      }

      return
    }

    obj[k] = _process(v, mod)
  }
}
The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.