pub fn focus_next(&mut self) {
        if self.len() < 2 {
            return;
        }
        self.before.push_back(self.after.pop_front().unwrap());
        if self.after.is_empty() {
            swap(&mut self.after, &mut self.before);
        }
    }
/// Shifts focus to the next element.
Shifts focus to the next element.
Shifts focus to the next element .
pub fn focus_next(&mut self) {
        if self.len() < 2 {
            return;
        }
        self.before.push_back(self.after.pop_front().unwrap());
        if self.after.is_empty() {
            swap(&mut self.after, &mut self.before);
        }
    }
pub fn focus_next ( & mut self ) { if self . len ( ) < 2 { return ; } self . before . push_back ( self . after . pop_front ( ) . unwrap ( ) ) ; if self . after . is_empty ( ) { swap ( & mut self . after , & mut self . before ) ; } }
Shifts focus to the next element.
Shifts focus to the next element .
&mut self