set(key, value = null) {
    if (!this.settingConfigs[key])
      throw new Error(`Invalid runtime setting: ${key}`);
    this.settings[key] = this.settingConfigs[key].validate(value);
  }
Set a runtime setting
- Will throw an error if the setting requested is not a supported runtime setting key
- Will validate the value against the setting's validate function
@param {string} key
@param {any} value
@returns {void}