90     pub fn is_empty(&self) -> bool {  in is_empty()  function
231     pub fn is_empty(&self) -> bool {  in is_empty()  function
390         assert!(s.is_empty());  in empty()
457         assert!(c.is_empty());  in two_level_sparse_tree()
462         assert!(!c.is_empty());  in two_level_sparse_tree()
480             assert!(!c.is_empty());  in two_level_sparse_tree()
485             assert!(!c.is_empty());  in two_level_sparse_tree()
492         assert!(c.is_empty());  in two_level_sparse_tree()
504         assert!(c.is_empty());  in three_level_sparse_tree()
509         assert!(!c.is_empty());  in three_level_sparse_tree()
527             assert!(!c.is_empty());  in three_level_sparse_tree()
532             assert!(!c.is_empty());  in three_level_sparse_tree()
539         assert!(c.is_empty());  in three_level_sparse_tree()
582             assert!(!c.is_empty());  in four_level()
603         assert!(c.is_empty());  in four_level()