docs: function createLogger (initConfiguration) {
    // Default to log level: warn (2)
    var level = logger.WARN;
    if (has(process.env, 'GCLOUD_ERRORS_LOGLEVEL')) {
      // Cast env string as integer
      level = ~~process.env.GCLOUD_ERRORS_LOGLEVEL;
    } else if (isObject(initConfiguration) && has(initConfiguration, 'logLevel')) {
      if (isString(initConfiguration.logLevel)) {
        // Cast string as integer
        level = ~~initConfiguration.logLevel;
      } else if (isNumber(initConfiguration.logLevel)) {
        level = initConfiguration.logLevel;
      } else {
        throw new Error('config.logLevel must be a number or decimal ' +
          'representation of a number in string form');
      }
    }
    return logger.create(level, '@google/cloud-errors');
  }