/// <summary>
/// Returns a new <see cref="CallSettings"/> with the specified retry settings,
/// merged with the (optional) original settings specified by <paramref name="settings"/>.
/// </summary>
/// <param name="settings">Original settings. May be null, in which case the returned settings
/// will only contain call timing.</param>
/// <param name="retry">Call timing for the new call settings.
/// This may be null, in which case any retry settings in <paramref name="settings"/> are
/// not present in the new call settings. If both this and <paramref name="settings"/> are null,
/// the return value is null.</param>
/// <returns>A new set of call settings, or null if both parameters are null.</returns>
public static CallSettings WithRetry(
this CallSettings settings,
RetrySettings retry) =>
settings == null
? CallSettings.FromRetry(retry)
: new CallSettings(settings.CancellationToken, settings.Credentials,
settings.Expiration, retry, settings.HeaderMutation,
settings.WriteOptions, settings.PropagationToken,
settings.ResponseMetadataHandler, settings.TrailingMetadataHandler);
/// <summary>
/// Returns a new <see cref="CallSettings"/> with the specified retry settings,
/// merged with the (optional) original settings specified by <paramref name="settings"/>.
/// </summary>
/// <param name="settings">Original settings. May be null, in which case the returned settings
/// will only contain call timing.</param>
/// <param name="retry">Call timing for the new call settings.
/// This may be null, in which case any retry settings in <paramref name="settings"/> are
/// not present in the new call settings. If both this and <paramref name="settings"/> are null,
/// the return value is null.</param>
/// <returns>A new set of call settings, or null if both parameters are null.</returns>
public static CallSettings WithRetry(
this CallSettings settings,
RetrySettings retry) =>
settings == null
? CallSettings.FromRetry(retry)
// But as long as user code can specify credentials we should continue to respect that.
: new CallSettings(settings.CancellationToken,
settings.Expiration, retry, settings.HeaderMutation,
settings.WriteOptions, settings.PropagationToken,
settings.ResponseMetadataHandler, settings.TrailingMetadataHandler);