(r'() => {}','function () {return {}}'),
# (r'\{\.\.\.(.+?)\}','Object.assign({}, \\1)') ,
# (r'(let|const) ', 'var '),
# (r'(\w+) \(\) \{', '\\1: function () {'),
# (r'(\s*)for \(var (\w+) of ([\w\.]+)\) \{', r'\1for (var i=0; i < \3.length; i++) {\1 var \2 = \3[i]')