Checks authorization of a rule against the target and credentials.

def enforce(self, rule, target, creds, exc=None, *args, **kwargs):
        """Checks authorization of a rule against the target and credentials."""

        self.load_rules()

        if isinstance(rule, checks.BaseCheck):
            result = rule(target, creds, self, rule)
        elif not self.rules:
            # No rules means we're going to fail closed.
            result = False
        else:
            try:
                # Evaluate the rule
                result = self.rules[rule](target, creds, self, rule)
            except KeyError:
                LOG.debug('Rule [%s] does not exist', rule)
                # If the rule doesn't exist, fail closed
                result = False

        if self.raise_error and not result:
            if exc:
                raise exc(*args, **kwargs)
            else:
                raise PolicyNotAuthorized(rule, target, creds)

        return result