Nullable value type may be null.

Non-nullable field 'random' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'next' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'random' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'next' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Nullable value type may be null.

Possible null reference argument for parameter 'item' in 'void Queue<TreeNode>.Enqueue(TreeNode item)'.

Converting null literal or possible null value to non-nullable type.

Non-nullable field 'right' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'left' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Cannot convert null literal to non-nullable reference type.

Non-nullable field 'random' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'next' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'random' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'next' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Possible null reference argument for parameter 'item' in 'void Queue<TreeNode>.Enqueue(TreeNode item)'.

Converting null literal or possible null value to non-nullable type.

Nullable value type may be null.

Non-nullable field 'right' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'left' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.