pub fn contains_joker(&self) -> bool {
        for card in &self.0 {
            if *card == Joker {
                return true;
            }
        }
        false
    }
/// Check if a sequence has a joker
///
/// # Example
///
/// ```
/// use machiavelli::sequence_cards::{ Sequence, Card::* , Suit::*};
///
/// let cards_1 = Sequence::from_cards(&[
///     RegularCard(Heart, 1),
///     RegularCard(Heart, 2),
///     Joker, 
///     RegularCard(Heart, 3),
///     RegularCard(Club, 11)
/// ]);
/// let cards_2 = Sequence::from_cards(&[
///     RegularCard(Heart, 1),
///     RegularCard(Heart, 2),
///     RegularCard(Heart, 3),
///     RegularCard(Club, 11)
/// ]);
///
/// assert_eq!(true, cards_1.contains_joker());
/// assert_eq!(false, cards_2.contains_joker());
/// ```
Check if a sequence has a joker
Check if a sequence has a joker
pub fn contains_joker(&self) -> bool {
        for card in &self.0 {
            if *card == Joker {
                return true;
            }
        }
        false
    }
pub fn contains_joker ( & self ) -> bool { for card in & self . 0 { if * card == Joker { return true ; } } false }
Check if a sequence has a joker
Check if a sequence has a joker
&self
&self
example
```
use machiavelli::sequence_cards::{ Sequence, Card::* , Suit::*}.

let cards_1 = Sequence::from_cards(&[
RegularCard(Heart, 1),
RegularCard(Heart, 2),
Joker,
RegularCard(Heart, 3),
RegularCard(Club, 11)
]);
let cards_2 = Sequence::from_cards(&[
RegularCard(Heart, 1),
RegularCard(Heart, 2),
RegularCard(Heart, 3),
RegularCard(Club, 11)
]).

assert_eq!(true, cards_1.contains_joker());
assert_eq!(false, cards_2.contains_joker());
```
` ` ` use machiavelli :: sequence_cards :: { Sequence Card :: * Suit :: * } . let cards_1 = Sequence :: from_cards ( & [ RegularCard ( Heart 1 ) RegularCard ( Heart 2 ) Joker RegularCard ( Heart 3 ) RegularCard ( Club 11 ) ] ) ; let cards_2 = Sequence :: from_cards ( & [ RegularCard ( Heart 1 ) RegularCard ( Heart 2 ) RegularCard ( Heart 3 ) RegularCard ( Club 11 ) ] ) . assert_eq! ( true cards_1 . contains_joker () ) ; assert_eq! ( false cards_2 . contains_joker () ) ; ` ` `