static defaultRetryParameters() {
    // Use a function rather than a constant member so the calling code can
    // modify the values without affecting other call results.
    return {
      maxAttempts: 2,
      baseDelay: 1000,
      backoffFactor: 2,
      fuzzFactor: 0.5,
      timeout: 30000,
      stallTimeout: 5000,
      connectionTimeout: 10000,
    };
  }
Gets a copy of the default retry parameters.

@return {shaka.extern.RetryParameters}