Protected Overrides Function GetIssuedClaims(ByVal RST As RequestSecurityToken) As Collection(Of SamlAttribute)

    Dim rstAppliesTo As EndpointAddress = RST.AppliesTo

    If rstAppliesTo Is Nothing Then
        Throw New InvalidOperationException("No AppliesTo EndpointAddress in RequestSecurityToken")
    End If

    Dim bookName As String = rstAppliesTo.Headers.FindHeader(Constants.BookNameHeaderName, Constants.BookNameHeaderNamespace).GetValue(Of String)()

    If String.IsNullOrEmpty(bookName) Then
        Throw New FaultException("The book name was not specified in the RequestSecurityToken")
    End If
    EnsurePurchaseLimitSufficient(bookName)

    Dim samlAttributes As New Collection(Of SamlAttribute)()

    Dim claimSet As ClaimSet
    For Each claimSet In ServiceSecurityContext.Current.AuthorizationContext.ClaimSets
        ' Copy Name claims from the incoming credentials into the set of claims we're going to issue
        Dim nameClaims As IEnumerable(Of Claim) = claimSet.FindClaims(ClaimTypes.Name, Rights.PossessProperty)
        If Not (nameClaims Is Nothing) Then
            Dim nameClaim As Claim
            For Each nameClaim In nameClaims
                samlAttributes.Add(New SamlAttribute(nameClaim))
            Next nameClaim
        End If
    Next claimSet
    ' add a purchase authorized claim
    samlAttributes.Add(New SamlAttribute(New Claim(Constants.PurchaseAuthorizedClaim, bookName, Rights.PossessProperty)))
    Return samlAttributes

End Function