def verify_in_strict_mode(self, filename):
    with open(filename) as infile:
        js = infile.read()
    filename += '.strict.js'
    with open(filename, 'w') as outfile:
        outfile.write(('"use strict";\n' + js))
    run_js(filename)
def verify_in_strict_mode(self, filename):
    with open(filename) as infile:
        js = infile.read()
    filename += '.strict.js'
    with open(filename, 'w') as outfile:
        outfile.write(('"use strict";\n' + js))
    run_js(filename)