'Returns whether or not this dependency is met for a given task instance. A
dependency is considered met if all of the dependency statuses it reports are
passing.
:param ti: the task instance to see if this dependency is met for
:type ti: TaskInstance
:param session: database session
:type session: Session
:param dep_context: The context this dependency is being checked under that stores
state that can be used by this dependency.
:type dep_context: BaseDepContext'

@provide_session
def is_met(self, ti, session, dep_context=None):

    return all((status.passed for status in self.get_dep_statuses(ti, session, dep_context)))
