anchor.diff:  		revert_try_expr(Node);
   	     tuple -> 
   		revert_tuple(Node);
  -	     underscore ->
  +             underscore ->
   		revert_underscore(Node);
   	     variable -> 
   		revert_variable(Node);
  
positive.code:     size_qualifier(N, A);
  make_tree(try_expr, [B, C, H, A]) ->
      try_expr(B, C, H, A);
  make_tree(tuple, [E]) -> tuple(E);
  make_tree(empty_node, []) -> empty_node(). 
  
  
negative.code: 	 macro_arguments/1, macro_name/1, make_tree/2,
  	 match_expr/2, match_expr_body/1, match_expr_pattern/1,
  	 meta/1, module_qualifier/2, module_qualifier_argument/1,
  	 module_qualifier_body/1,
           named_fun_expr/2,
  	 named_fun_expr_arity/1,
  	 named_fun_expr_clauses/1,
  	 named_fun_expr_name/1,
           map_elements/1,
           map_field_elements/1,
           nil/0, normalize_list/1,
  	 operator/1, operator_literal/1, operator_name/1,
  	 parentheses/1, parentheses_body/1,
           fake_parentheses/1, fake_parentheses_body/1,
  