  remove(id) {
    if (typeof id !== 'number' || id < 0 || id >= MAX_CHANNEL || !isFinite(id))
      throw new Error(`Invalid channel id: ${id}`);

    if (this._channels[id]) {
      delete this._channels[id];
      if (this._count)
        --this._count;
    }
  }
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.