def validate_signed_elements(self, signed_elements):
        """
        Verifies that the document has the expected signed nodes.

        :param signed_elements: The signed elements to be checked
        :type signed_elements: list

        :param raise_exceptions: Whether to return false on failure or raise an exception
        :type raise_exceptions: Boolean
        """
        if len(signed_elements) > 2:
            return False

        response_tag = '{%s}Response' % OneLogin_Saml2_Constants.NS_SAMLP
        assertion_tag = '{%s}Assertion' % OneLogin_Saml2_Constants.NS_SAML

        if (response_tag in signed_elements and signed_elements.count(response_tag) > 1) or \
           (assertion_tag in signed_elements and signed_elements.count(assertion_tag) > 1) or \
           (response_tag not in signed_elements and assertion_tag not in signed_elements):
            return False

        # Check that the signed elements found here, are the ones that will be verified
        # by OneLogin_Saml2_Utils.validate_sign
        if response_tag in signed_elements:
            expected_signature_nodes = OneLogin_Saml2_Utils.query(self.document, OneLogin_Saml2_Utils.RESPONSE_SIGNATURE_XPATH)
            if len(expected_signature_nodes) != 1:
                raise OneLogin_Saml2_ValidationError(
                    'Unexpected number of Response signatures found. SAML Response rejected.',
                    OneLogin_Saml2_ValidationError.WRONG_NUMBER_OF_SIGNATURES_IN_RESPONSE
                )

        if assertion_tag in signed_elements:
            expected_signature_nodes = self.__query(OneLogin_Saml2_Utils.ASSERTION_SIGNATURE_XPATH)
            if len(expected_signature_nodes) != 1:
                raise OneLogin_Saml2_ValidationError(
                    'Unexpected number of Assertion signatures found. SAML Response rejected.',
                    OneLogin_Saml2_ValidationError.WRONG_NUMBER_OF_SIGNATURES_IN_ASSERTION
                )

        return True
Verifies that the document has the expected signed nodes.

        :param signed_elements: The signed elements to be checked
        :type signed_elements: list

        :param raise_exceptions: Whether to return false on failure or raise an exception
        :type raise_exceptions: Boolean