'Is my return_to under my trust_root?
@returntype: bool'

def trustRootValid(self):

    if (not self.trust_root):
        return True
    tr = TrustRoot.parse(self.trust_root)
    if (tr is None):
        raise MalformedTrustRoot(self.message, self.trust_root)
    if (self.return_to is not None):
        return tr.validateURL(self.return_to)
    else:
        return True
