pub fn common_subscriptions<'a>(&'a self, other: &'a Self) -> impl Iterator<Item = &'a Topic> {
        self.0
            .keys()
            .filter(move |topic| other.0.contains_key(topic))
    }
/// retrieve the iterator over the topics common between both subscriptions
retrieve the iterator over the topics common between both subscriptions
retrieve the iterator over the topics common between both subscriptions
pub fn common_subscriptions<'a>(&'a self, other: &'a Self) -> impl Iterator<Item = &'a Topic> {
        self.0
            .keys()
            .filter(move |topic| other.0.contains_key(topic))
    }
pub fn common_subscriptions < ' a > ( & ' a self , other : & ' a Self ) -> impl Iterator < Item = & ' a Topic > { self . 0 . keys ( ) . filter ( move | topic | other . 0 . contains_key ( topic ) ) }
retrieve the iterator over the topics common between both subscriptions
retrieve the iterator over the topics common between both subscriptions
&'a self
other
&'a Self