/// <summary>
/// Gets an individual policy.
/// </summary>
/// <param name="list"></param>
/// <param name="policyInterface">The interface the policy is registered under.</param>
/// <param name="buildKey">The key the policy applies.</param>
/// <param name="containingPolicyList">The policy list in the chain that the searched for policy was found in, null if the policy was
/// not found.</param>
/// <returns>The policy in the list, if present; returns null otherwise.</returns>
public static IBuilderPolicy GetOrDefault(this IPolicyList list, Type policyInterface, object buildKey, out IPolicyList containingPolicyList)
{
Type buildType;
if (buildKey is INamedType basedBuildKey)
{
buildType = basedBuildKey.Type;
}
else
{
buildType = buildKey as Type;
}
return(list.GetPolicyForKey(policyInterface, buildKey, out containingPolicyList) ??
list.GetPolicyForOpenGenericKey(policyInterface, buildKey, buildType, out containingPolicyList) ??
list.GetPolicyForType(policyInterface, buildType, out containingPolicyList) ??
list.GetPolicyForOpenGenericType(policyInterface, buildType, out containingPolicyList) ??
list.GetDefaultForPolicy(policyInterface, out containingPolicyList));
}
