def get_incomplete_context_data(self, interfaces):
        '''
        Return dictionary of relation status of interfaces and any missing
        required context data. Example:
            {'amqp': {'missing_data': ['rabbitmq_password'], 'related': True},
             'zeromq-configuration': {'related': False}}
        '''
        incomplete_context_data = {}

        for i in six.itervalues(self.templates):
            for context in i.contexts:
                for interface in interfaces:
                    related = False
                    if interface in context.interfaces:
                        related = context.get_related()
                        missing_data = context.missing_data
                        if missing_data:
                            incomplete_context_data[interface] = {'missing_data': missing_data}
                        if related:
                            if incomplete_context_data.get(interface):
                                incomplete_context_data[interface].update({'related': True})
                            else:
                                incomplete_context_data[interface] = {'related': True}
                        else:
                            incomplete_context_data[interface] = {'related': False}
        return incomplete_context_data
Return dictionary of relation status of interfaces and any missing
        required context data. Example:
            {'amqp': {'missing_data': ['rabbitmq_password'], 'related': True},
             'zeromq-configuration': {'related': False}}