unittest for nested function

[fstefanov]

Hello all,

Have to write couple unittests for nested function.
This is simplified version

def processSubscription(
        self,
        command,
        **conditions
):
    def _matchConditions(request_conditions, command_conditions):
        if request_conditions in command_conditions:
            return True
        else
            return False

    if _matchConditions(conditions, command_conditions):
        subscribers = subscription['emails']
        send_mail(subscribers)

I want to capture the return value from _matchConditions
for my tests and also mock send_mail function,
so mails are not actually send on match.