method creates a sample tree 5 4 6 3 7 8 concode_field_sep int data concode_elem_sep TreeNode left concode_elem_sep TreeNode root concode_elem_sep TreeNode right concode_field_sep void main concode_elem_sep void iterativePreorder
void function ( ) { root = new TreeNode ( 5 ) ; root . left = new TreeNode ( 4 ) ; root . right = new TreeNode ( 6 ) ; root . left . left = new TreeNode ( 3 ) ; root . left . right = new TreeNode ( 7 ) ; root . right . left = new TreeNode ( 8 ) ; }