  double TextureStrength() const {
    const auto it = json_double_value.find("strength");
    if (it != std::end(json_double_value)) {
      return it->second;
    }
    // As per the spec, if strenghth is ommited, this parameter is 1
    return 1;
  }
  double TextureStrength() const {
    const auto it = json_double_value.find("strength");
    if (it != std::end(json_double_value)) {
      return it->second;
    }
     
    return 1;
  }