Specifies a list of trusted ID evaluators that determine whether
to trust the identity-asserting authority or message sender.
The trusted ID evaluators are used to authenticate additional identities
from one server to another server. For example, a client sends the identity
of user A to server 1 for authentication. Server 1 calls downstream to server
2, asserts the identity of user A, and includes the user name and password
of server 1. Server 2 attempts to establish trust with server 1 by authenticating
its user name and password and checking the trust based on the TrustedIDEvaluator
implementation. If the authentication process and the trust check are successful,
server 2 trusts that server 1 authenticated user A and a credential is created
for user A on server 2 to invoke the request.