/// <summary>
/// <para> Builds a <see cref="Policy"/> that will function like a Circuit Breaker.</para>
/// <para>The circuit will break after <paramref name="exceptionsAllowedBeforeBreaking"/>
/// exceptions that are handled by this policy are raised. The circuit will stay
/// broken for the <paramref name="durationOfBreak"/>. Any attempt to execute this policy
/// while the circuit is broken, will immediately throw a <see cref="BrokenCircuitException"/> containing the exception
/// that broke the cicuit.
/// </para>
/// <para>If the first action after the break duration period results in an exception, the circuit will break
/// again for another <paramref name="durationOfBreak"/>, otherwise it will reset.
/// </para>
/// </summary>
/// <param name="policyBuilder">The policy builder.</param>
/// <param name="exceptionsAllowedBeforeBreaking">The number of exceptions that are allowed before opening the circuit.</param>
/// <param name="durationOfBreak">The duration the circuit will stay open before resetting.</param>
/// <returns>The policy instance.</returns>
/// <remarks>(see "Release It!" by Michael T. Nygard fi)</remarks>
/// <exception cref="System.ArgumentOutOfRangeException">exceptionsAllowedBeforeBreaking;Value must be greater than zero.</exception>
public static Policy CircuitBreakerAsync(this PolicyBuilder policyBuilder, int exceptionsAllowedBeforeBreaking, TimeSpan durationOfBreak)
{
if (exceptionsAllowedBeforeBreaking <= 0)
{
throw new ArgumentOutOfRangeException("exceptionsAllowedBeforeBreaking", "Value must be greater than zero.");
}
var policyState = new CircuitBreakerState(exceptionsAllowedBeforeBreaking, durationOfBreak);
return(new Policy(action => CircuitBreakerPolicy.ImplementationAsync(action, policyBuilder.ExceptionPredicates, policyState)));
}