pub fn is_contiguous(&self) -> bool {
        let mut h = HashSet::new();
        self.is_contiguous_helper(0, &mut h);
        h.len() == self.size()
    }
/// Returns true if this graph is contiguous.
Returns true if this graph is contiguous.
Returns true if this graph is contiguous .
pub fn is_contiguous(&self) -> bool {
        let mut h = HashSet::new();
        self.is_contiguous_helper(0, &mut h);
        h.len() == self.size()
    }
pub fn is_contiguous ( & self ) -> bool { let mut h = HashSet :: new ( ) ; self . is_contiguous_helper ( 0 , & mut h ) ; h . len ( ) == self . size ( ) }
Returns true if this graph is contiguous.
Returns true if this graph is contiguous .
&self