'Verifies that the action is valid on the target in this context.
:param context: Heat request context
:param rule: String representing the action to be checked
:param target: Dictionary representing the object of the action.
:raises: self.exc (defaults to heat.common.exception.Forbidden)
:returns: A non-False value if access is allowed.'

def _check(self, context, rule, target, exc, *args, **kwargs):

    do_raise = (False if (not exc) else True)
    credentials = context.to_policy_values()
    return self.enforcer.enforce(rule, target, credentials, do_raise, exc=exc, *args, **kwargs)
