*/
public RequestSecurityToken createRSTForIssue(URI tokenType, URI requestType, URI context, AppliesTo scopes,
Claims claims, Entropy entropy, Lifetime lt) throws WSTrustException {
// if (tokenType==null || scopes==null)
// throw new WSTrustException("TokenType and AppliesTo cannot be both null");
RequestSecurityToken rst = new RequestSecurityTokenImpl(tokenType, requestType, context, scopes, claims, entropy, lt, null);
return rst;
}