anchor.diff:  
   %% Add location data metadata to any node
   -spec add_location_data(es_node(),
  -                      pos_integer(),
  -                      non_neg_integer(),
  -                      non_neg_integer()) -> es_node().
  +                        pos_integer(),
  +                        non_neg_integer(),
  +                        non_neg_integer()) -> es_node().
   add_location_data(Node, LineNumber, ColStart, ColEnd) ->
       update_record(Node, [{"loc", source_location(LineNumber, ColStart, ColEnd)}]).
   
  
positive.code: spread_element(Argument) ->
      %?spec([{Argument, [identifier, arrayExpression]}]),
      update_record(node(), [{"type", <<"SpreadElement">>},
                            {"argument", Argument}]).
  
  
  
  
negative.code: 
  %% Generate a function declaration
  -spec function_declaration(identifier_node(),
                             [identifier_node()],
                             block_statement_node()) -> function_declaration_node().
  function_declaration(Identifier, Params, Body) ->
      %?spec([{Identifier, identifier}, {Params, list_of_identifier}, {Body, [expression, blockStatement]}]),
      update_record(declaration(), [{"type", <<"FunctionDeclaration">>},
                                    {"id", Identifier},
                                    {"params", Params},
                                    {"body", Body}]).
  
  
  
  