             print(btree)
             btree.remove(hashValue: 2)
             print(btree)
-            try? btree.insert(2)
+            try! btree.insert(2)
             let interval = 0..<50
             for i in interval { try? btree.insert(i) }
             XCTAssert(btree.count == 50)

                XCTAssert(!btree.contains(r))
            }
            
            try? btree.insert(2)
            print(btree)
        }
    }

            
            for i in interval { btree.replace(i) }
            
            let a = (try? btree.insert(47)) == nil
            XCTAssert(a)
            
            let bheight2 = btree.height
            XCTAssert(bheight2 >= minHeight || bheight2 <= maxHeight, "\(bheight2) \(minHeight) \(maxHeight) \(i)")
            
